n. [ OE. stem, steem, vapor, flame, AS. steám vapor, smoke, odor; akin to D. stoom steam, perhaps originally, a pillar, or something rising like a pillar; cf. Gr. sty`ein to erect, sty^los a pillar, and E. stand. ] 1. The elastic, aeriform fluid into which water is converted when heated to the boiling point; water in the state of vapor; gaseous water. [ 1913 Webster + PJC ]

2. The mist formed by condensed vapor; visible vapor; -- so called in popular usage. [ 1913 Webster ]

3. Any exhalation. “A steam of rich, distilled perfumes.” Milton. [ 1913 Webster ]

Dry steam, steam which does not contain water held in suspension mechanically; -- sometimes applied to superheated steam. --
Exhaust steam. See under Exhaust. --
High steam, or
High-pressure steam, steam of which the pressure greatly exceeds that of the atmosphere. --
Low steam, or
Low-pressure steam, steam of which the pressure is less than, equal to, or not greatly above, that of the atmosphere. --
Saturated steam, steam at the temperature of the boiling point which corresponds to its pressure; -- sometimes also applied to wet steam. --
Superheated steam, steam heated to a temperature higher than the boiling point corresponding to its pressure. It can not exist in contact with water, nor contain water, and resembles a perfect gas; -- called also surcharged steam, anhydrous steam, and steam gas. --
Wet steam, steam which contains water held in suspension mechanically; -- called also misty steam. [ 1913 Webster ]

☞ Steam is often used adjectively, and in combination, to denote, produced by heat, or operated by power, derived from steam, in distinction from other sources of power; as in steam boiler or steam-boiler, steam dredger or steam-dredger, steam engine or steam-engine, steam heat, steam plow or steam-plow, etc. [ 1913 Webster ]

Steam blower. (a) A blower for producing a draught consisting of a jet or jets of steam in a chimney or under a fire. (b) A fan blower driven directly by a steam engine. --
Steam boiler, a boiler for producing steam. See Boiler, 3, and Note. In the illustration, the shell a of the boiler is partly in section, showing the tubes, or flues, which the hot gases, from the fire beneath the boiler, enter, after traversing the outside of the shell, and through which the gases are led to the smoke pipe d, which delivers them to the chimney; b is the manhole; c the dome; e the steam pipe; f the feed and blow-off pipe; g the safety valve; hthe water gauge. --
Steam car, a car driven by steam power, or drawn by a locomotive. --
Steam carriage, a carriage upon wheels moved on common roads by steam. --
Steam casing. See Steam jacket, under Jacket. --
Steam chest, the box or chamber from which steam is distributed to the cylinder of a steam engine, steam pump, etc., and which usually contains one or more valves; -- called also valve chest, and valve box. See Illust. of Slide valve, under Slide. --
Steam chimney, an annular chamber around the chimney of a boiler furnace, for drying steam. --
Steam coil, a coil of pipe, or a collection of connected pipes, for containing steam; -- used for heating, drying, etc. --
Steam colors (Calico Printing), colors in which the chemical reaction fixing the coloring matter in the fiber is produced by steam. --
Steam cylinder, the cylinder of a steam engine, which contains the piston. See Illust. of Slide valve, under Slide. --
Steam dome (Steam Boilers), a chamber upon the top of the boiler, from which steam is conducted to the engine. See Illust. of Steam boiler, above. --
Steam fire engine, a fire engine consisting of a steam boiler and engine, and pump which is driven by the engine, combined and mounted on wheels. It is usually drawn by horses, but is sometimes made self-propelling. --
Steam fitter, a fitter of steam pipes. --
Steam fitting, the act or the occupation of a steam fitter; also, a pipe fitting for steam pipes. --
Steam gas. See Superheated steam, above. --
Steam gauge, an instrument for indicating the pressure of the steam in a boiler. The mercurial steam gauge is a bent tube partially filled with mercury, one end of which is connected with the boiler while the other is open to the air, so that the steam by its pressure raises the mercury in the long limb of the tube to a height proportioned to that pressure. A more common form, especially for high pressures, consists of a spring pressed upon by the steam, and connected with the pointer of a dial. The spring may be a flattened, bent tube, closed at one end, which the entering steam tends to straighten, or it may be a diaphragm of elastic metal, or a mass of confined air, etc. --
Steam gun, a machine or contrivance from which projectiles may be thrown by the elastic force of steam. --
Steam hammer, a hammer for forging, which is worked directly by steam; especially, a hammer which is guided vertically and operated by a vertical steam cylinder located directly over an anvil. In the variety known as Nasmyth's, the cylinder is fixed, and the hammer is attached to the piston rod. In that known as Condie's, the piston is fixed, and the hammer attached to the lower end of the cylinder. --
Steam heater. (a) A radiator heated by steam. (b) An apparatus consisting of a steam boiler, radiator, piping, and fixures for warming a house by steam. --
Steam jacket. See under Jacket. --
Steam packet, a packet or vessel propelled by steam, and running periodically between certain ports. --
Steam pipe, any pipe for conveying steam; specifically, a pipe through which steam is supplied to an engine. --
Steam plow or
Steam plough, a plow, or gang of plows, moved by a steam engine. --
Steam port, an opening for steam to pass through, as from the steam chest into the cylinder. --
Steam power, the force or energy of steam applied to produce results; power derived from a steam engine. --
Steam propeller. See Propeller. --
Steam pump, a small pumping engine operated by steam. It is usually direct-acting. --
Steam room (Steam Boilers), the space in the boiler above the water level, and in the dome, which contains steam. --
Steam table, a table on which are dishes heated by steam for keeping food warm in the carving room of a hotel, restaurant, etc. --
Steam trap, a self-acting device by means of which water that accumulates in a pipe or vessel containing steam will be discharged without permitting steam to escape. --
Steam tug, a steam vessel used in towing or propelling ships. --
Steam vessel, a vessel propelled by steam; a steamboat or steamship; a steamer. --
Steam whistle, an apparatus attached to a steam boiler, as of a locomotive, through which steam is rapidly discharged, producing a loud whistle which serves as a warning or a signal. The steam issues from a narrow annular orifice around the upper edge of the lower cup or hemisphere, striking the thin edge of the bell above it, and producing sound in the manner of an organ pipe or a common whistle. [ 1913 Webster ]

v. i. [ imp. & p. p. Steamed p. pr. & vb. n. Steaming. ] 1. To emit steam or vapor. [ 1913 Webster ]

My brother's ghost hangs hovering there,
O'er his warm blood, that steams into the air. Dryden. [ 1913 Webster ]

Let the crude humors dance
In heated brass, steaming with fire intense. J. Philips. [ 1913 Webster ]

2. To rise in vapor; to issue, or pass off, as vapor. [ 1913 Webster ]

The dissolved amber . . . steamed away into the air. Boyle. [ 1913 Webster ]

3. To move or travel by the agency of steam. [ 1913 Webster ]

The vessel steamed out of port. N. P. Willis. [ 1913 Webster ]

4. To generate steam; as, the boiler steams well. [ 1913 Webster ]

v. t. 1. To exhale. [ Obs. ] Spenser. [ 1913 Webster ]

2. To expose to the action of steam; to apply steam to for softening, dressing, or preparing; as, to steam wood; to steamcloth; to steam food, etc. [ 1913 Webster ]

n. A boat or vessel propelled by steam power; -- generally used of river or coasting craft, as distinguished from ocean steamers. [ 1913 Webster ]

n. 1. The occupation or business of running a steamboat, or of transporting merchandise, passengers, etc., by steamboats. [ 1913 Webster ]

2. (Bookbinding) The shearing of a pile of books which are as yet uncovered, or out of boards. Knight. [ 1913 Webster ]

An engine moved by steam. [ 1913 Webster ]

☞ In its most common forms its essential parts are a piston, a cylinder, and a valve gear. The piston works in the cylinder, to which steam is admitted by the action of the valve gear, and communicates motion to the machinery to be actuated. Steam engines are thus classified: 1. According to the way the steam is used or applied, as condensing, noncondensing, compound, double-acting, single-acting, triple-expansion, etc. 2. According to the motion of the piston, as reciprocating, rotary, etc. 3. According to the motion imparted by the engine, as rotative and nonrotative. 4. According to the arrangement of the engine, as stationary, portable, and semiportable engines, horizontal and vertical engines, beam engine, oscillating engine, direct-acting and back-acting engines, etc. 5. According to their uses, as portable, marine, locomotive, pumping, blowing, winding, and stationary engines, the latter term referring to factory engines, etc., and not technically to pumping or blowing engines. Locomotive and portable engines are usually high-pressure, noncondensing, rotative, and direct-acting. Marine engines are high or low pressure, rotative, and generally condensing, double-acting, and compound. Paddle engines are generally beam, side-lever, oscillating, or direct-acting. Screw engines are generally direct-acting, back-acting, or oscillating. Stationary engines belong to various classes, but are generally rotative. A horizontal or inclined stationary steam engine is called a left-hand or a right-hand engine when the crank shaft and driving pulley are on the left-hand side, or the right-hand side, respectively, of the engine, to a person looking at them from the cylinder, and is said to run forward or backward when the crank traverses the upward half, or lower half, respectively, of its path, while the piston rod makes its stroke outward from the cylinder. A marine engine, or the engine of a locomotive, is said to run forward when its motion is such as would propel the vessel or the locomotive forward. Steam engines are further classified as double-cylinder, disk, semicylinder, trunk engines, etc. Machines, such as cranes, hammers, etc., of which the steam engine forms a part, are called steam cranes, steam hammers, etc. See Illustration in Appendix. [ 1913 Webster ]

Back-acting steam engine, or
Back-action steam engine, a steam engine in which the motion is transmitted backward from the crosshead to a crank which is between the crosshead and the cylinder, or beyond the cylinder. --
Portable steam engine, a steam engine combined with, and attached to, a boiler which is mounted on wheels so as to admit of easy transportation; -- used for driving machinery in the field, as thrashing machines, draining pumps, etc. --
Semiportable steam engine, a steam engine combined with, and attached to, a steam boiler, but not mounted on wheels. [ 1913 Webster ]

n. 1. A vessel propelled by steam; a steamship or steamboat. [ 1913 Webster ]

2. A steam fire engine. See under Steam. [ 1913 Webster ]

3. A road locomotive for use on common roads, as in agricultural operations. [ 1913 Webster ]

4. A vessel in which articles are subjected to the action of steam, as in washing, in cookery, and in various processes of manufacture. [ 1913 Webster ]

5. (Zool.) The steamer duck. [ 1913 Webster ]

Steamer duck (Zool.), a sea duck (Tachyeres cinereus), native of Patagonia and Terra del Fuego, which swims and dives with great agility, but which, when full grown, is incapable of flight, owing to its very small wings. Called also loggerhead, race horse, and side-wheel duck. [ 1913 Webster ]

n. The quality or condition of being steamy; vaporousness; mistiness. [ 1913 Webster ]

n. A ship or seagoing vessel propelled by the power of steam; a steamer. [ 1913 Webster ]

v. t. To cause to be covered by a translucent layer of condensed water in fine droplets, such as by breathing on a cold window; to fog; as, to steam up one's eyeglasses. [ PJC ]