a. [ Compar. Sourer superl. Sourest. ] [ OE. sour, sur, AS. s&unr_;r; akin to D. zuur, G. sauer, OHG. s&unr_;r, Icel. s&unr_;rr, Sw. sur, Dan. suur, Lith. suras salt, Russ. surovui harsh, rough. Cf. Sorrel, the plant. ] 1. Having an acid or sharp, biting taste, like vinegar, and the juices of most unripe fruits; acid; tart. [ 1913 Webster ]

All sour things, as vinegar, provoke appetite. Bacon. [ 1913 Webster ]

2. Changed, as by keeping, so as to be acid, rancid, or musty, turned. [ 1913 Webster ]

3. Disagreeable; unpleasant; hence; cross; crabbed; peevish; morose; as, a man of a sour temper; a sour reply. “A sour countenance.” Swift. [ 1913 Webster ]

He was a scholar . . .
Lofty and sour to them that loved him not,
But to those men that sought him sweet as summer. Shak. [ 1913 Webster ]

4. Afflictive; painful. “Sour adversity.” Shak. [ 1913 Webster ]

5. Cold and unproductive; as, sour land; a sour marsh. [ 1913 Webster ]

Sour dock (Bot.), sorrel. --
Sour gourd (Bot.), the gourdlike fruit Adansonia Gregorii, and Adansonia digitata; also, either of the trees bearing this fruit. See Adansonia. --
Sour grapes. See under Grape. --
Sour gum (Bot.) See Turelo. --
Sour plum (Bot.), the edible acid fruit of an Australian tree (Owenia venosa); also, the tree itself, which furnished a hard reddish wood used by wheelwrights. [ 1913 Webster ]

Syn. -- Acid; sharp; tart; acetous; acetose; harsh; acrimonious; crabbed; currish; peevish. [ 1913 Webster ]

v. t. [ AS. s&unr_;rian to sour, to become sour. ] 1. To cause to become sour; to cause to turn from sweet to sour; as, exposure to the air sours many substances. [ 1913 Webster ]

So the sun's heat, with different powers,
Ripens the grape, the liquor sours. Swift. [ 1913 Webster ]

2. To make cold and unproductive, as soil. Mortimer. [ 1913 Webster ]

3. To make unhappy, uneasy, or less agreeable. [ 1913 Webster ]

To sour your happiness I must report,
The queen is dead. Shak. [ 1913 Webster ]

4. To cause or permit to become harsh or unkindly. “Souring his cheeks.” Shak. [ 1913 Webster ]

Pride had not sour'd nor wrath debased my heart. Harte. [ 1913 Webster ]

5. To macerate, and render fit for plaster or mortar; as, to sour lime for business purposes. [ 1913 Webster ]

n. A sour or acid substance; whatever produces a painful effect. Spenser. [ 1913 Webster ]

v. i. [ imp. & p. p. Soured p. pr. & vb. n. Souring. ] To become sour; to turn from sweet to sour; as, milk soon sours in hot weather; a kind temper sometimes sours in adversity. [ 1913 Webster ]

They keep out melancholy from the virtuous, and hinder the hatred of vice from souring into severity. Addison. [ 1913 Webster ]

n. [ OE. sours, OF. sourse, surse, sorse, F. source, fr. OF. sors, p. p. of OF. sordre, surdre, sourdre, to spring forth or up, F. sourdre, fr. L. surgere to lift or raise up, to spring up. See Surge, and cf. Souse to plunge or swoop as a bird upon its prey. ] 1. The act of rising; a rise; an ascent. [ Obs. ] [ 1913 Webster ]

Therefore right as an hawk upon a sours
Up springeth into the air, right so prayers . . .
Maken their sours to Goddes ears two. Chaucer. [ 1913 Webster ]

2. The rising from the ground, or beginning, of a stream of water or the like; a spring; a fountain. [ 1913 Webster ]

Where as the Poo out of a welle small
Taketh his firste springing and his sours. Chaucer. [ 1913 Webster ]

Kings that rule
Behind the hidden sources of the Nile. Addison. [ 1913 Webster ]

3. That from which anything comes forth, regarded as its cause or origin; the person from whom anything originates; first cause. [ 1913 Webster ]

This source of ideas every man has wholly in himself. Locke. [ 1913 Webster ]

The source of Newton's light, of Bacon's sense. Pope. [ 1913 Webster ]

Syn. -- See Origin. [ 1913 Webster ]

n. See Sauerkraut. [ 1913 Webster ]

v. i. [ F. sourdre. See Source. ] To have origin or source; to rise; to spring. [ Obs. ] [ 1913 Webster ]

Now might men ask whereof that pride sourdeth. Chaucer. [ 1913 Webster ]

n. (Bot.) Any sour apple. [ 1913 Webster ]

a. Somewhat sour; moderately acid; as, sourish fruit; a sourish taste. [ 1913 Webster ]

n. Same as Sauerkraut. [ 1913 Webster ]