n.; pl. Alkalis or Alkalies [ F. alcali, ultimately fr. Ar. alqalī ashes of the plant saltwort, fr. qalay to roast in a pan, fry. ] 1. Soda ash; caustic soda, caustic potash, etc. [ 1913 Webster ]

2. (Chem.) One of a class of caustic bases, such as soda, potash, ammonia, and lithia, whose distinguishing peculiarities are solubility in alcohol and water, uniting with oils and fats to form soap, neutralizing and forming salts with acids, turning to brown several vegetable yellows, and changing reddened litmus to blue. [ 1913 Webster ]

3. Soluble mineral matter, other than common salt, contained in soils of natural waters. [ Western U. S. ] [ Webster 1913 Suppl. ]

Fixed alkalies, potash and soda. --
Vegetable alkalies. Same as Alkaloids. --
Volatile alkali, ammonia, so called in distinction from the fixed alkalies. [ 1913 Webster ]

adj. 1. having the properties of an alkali. Opposite of acidic. when used of aqueous solutions, it signifies that the solution has a pH greater than 7.
Syn. -- alkaline (vs. acidic), basic [ WordNet 1.5 ]

a. [ Cf. F. alcalifiable. ] Capable of being alkalified, or converted into an alkali. [ 1913 Webster ]

. A sterile plain, containing an excess of alkali, at the bottom of an undrained basin in an arid region; a playa. [ Webster 1913 Suppl. ]

v. i. To become changed into an alkali. [ 1913 Webster ]

v. t. [ imp. & p. p. Alkalified p. pr. & vb. n. Alkalifying. ] [ Alkali + -fly: cf. F. alcalifier. ] To convert into an alkali; to give alkaline properties to. [ 1913 Webster ]

. Any one of the univalent metals of group I of the periodic table of the elements, including lithium, sodium, potassium, rubidium, cesium, and francium. The hydroxides of these metals are soluble in water and form strongly basic solutions. [ PJC. ]

n. [ Alkali + -meter. cf. F. alcalimètre. ] An instrument to ascertain the strength of alkalies, or the quantity of alkali in a mixture. [ 1913 Webster ]

{ } a. Of or pertaining to alkalimetry. [ 1913 Webster ]

n. [ Cf. F. alcalimètrie. ] (Chem.) The art or process of ascertaining the strength of alkalies, or the quantity present in alkaline mixtures. [ 1913 Webster ]

a. [ Cf. F. alcalin. ] Of or pertaining to an alkali or to alkalies; having the properties of an alkali. [ 1913 Webster ]

Alkaline earths, certain substances, as lime, baryta, strontia, and magnesia, possessing some of the qualities of alkalies. --
Alkaline metals, potassium, sodium, cæsium, lithium, rubidium. --
Alkaline reaction, a reaction indicating alkalinity, as by the action on limits, turmeric, etc. [ 1913 Webster ]

adj. 1. thriving in a relatively alkaline environment; (especially of plants requiring a pH above 7) acid-loving
Syn. -- alkali-loving [ WordNet 1.5 ]

n. The quality which constitutes an alkali; alkaline property. Thomson. [ 1913 Webster ]

a. Alkaline. [ Obs. ] [ 1913 Webster ]

. Any one of various soils found in arid and semiarid regions, containing an unusual amount of soluble mineral salts which effloresce in the form of a powder or crust (usually white) in dry weather following rains or irrigation. The basis of these salts is mainly soda with a smaller amount of potash, and usually a little lime and magnesia. Two main classes of alkali are commonly distinguished: black alkali, which may be any alkaline carbonate, but which practically consists of sodium carbonate (sal soda), which is highly corrosive and destructive to vegetation; and white alkali, characterized by the presence of sodium sulphate (Glauber's salt), which is less injurious to vegetation. Black alkali is so called because water containing it dissolves humus, forming a dark-colored solution which, when it collects in puddles and evaporates, produces characteristic black spots. [ Webster 1913 Suppl. ]

. Waste material from the manufacture of alkali; specif., soda waste. [ Webster 1913 Suppl. ]

a. Alkaline. [ Obs. ] Boyle. [ 1913 Webster ]

v. t. To alkalizate. [ R. ] Johnson. [ 1913 Webster ]

n. [ Cf. F. alcalisation. ] The act of rendering alkaline by impregnating with an alkali; a conferring of alkaline qualities. [ 1913 Webster ]

v. t. [ imp. & p. p. Alkalized p. pr. & vb. n. Alkalizing ] [ Cf. F. alcaliser. ] To render alkaline; to communicate the properties of an alkali to. [ 1913 Webster ]

/mhw>, n. [ Pref. anti- + alkali. ] Anything that neutralizes, or that counteracts an alkaline tendency in the system. Hooper. [ 1913 Webster ]

a. Of power to counteract alkalies. [ 1913 Webster ]