Leaven

leaven
    n 1: a substance used to produce fermentation in dough or a
         liquid [syn: {leaven}, {leavening}]
    2: an influence that works subtly to lighten or modify
       something; "his sermons benefited from a leavening of humor"
       [syn: {leaven}, {leavening}]
    v 1: cause to puff up with a leaven; "unleavened bread" [syn:
         {raise}, {leaven}, {prove}]
    

Leaven \Leav"en\, v. t. [imp. & p. p. {Leavened}; p. pr. & vb.
   n. {Leavening}.]
   1. To make light by the action of leaven; to cause to
      ferment.
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            A little leaven leaveneth the whole lump. --1 Cor.
                                                  v. 6.
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   2. To imbue; to infect; to vitiate.
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            With these and the like deceivable doctrines, he
            leavens also his prayer.              --Milton.
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Leaven \Leav"en\, n. [OE. levain, levein, F. levain, L. levamen
   alleviation, mitigation; but taken in the sense of, a
   raising, that which raises, fr. levare to raise. See {Lever},
   n.]
   1. Any substance that produces, or is designed to produce,
      fermentation, as in dough or liquids; esp., a portion of
      fermenting dough, which, mixed with a larger quantity of
      dough, produces a general change in the mass, and renders
      it light; yeast; barm.
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   2. Anything which makes a general assimilating (especially a
      corrupting) change in the mass.
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            Beware of the leaven of the Pharisees, which is
            hypocrisy.                            --Luke xii. 1.
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Leaven
(1.) Heb. seor (Ex. 12:15, 19; 13:7; Lev. 2:11), the remnant of
dough from the preceding baking which had fermented and become
acid.

  (2.) Heb. hamets, properly "ferment." In Num. 6:3, "vinegar of
wine" is more correctly "fermented wine." In Ex. 13:7, the
proper rendering would be, "Unfermented things [Heb. matstsoth]
shall be consumed during the seven days; and there shall not be
seen with thee fermented things [hamets], and there shall not be
seen with thee leavened mass [seor] in all thy borders." The
chemical definition of ferment or yeast is "a substance in a
state of putrefaction, the atoms of which are in a continual
motion."

  The use of leaven was strictly forbidden in all offerings made
to the Lord by fire (Lev. 2:11; 7:12; 8:2; Num. 6:15). Its
secretly penetrating and diffusive power is referred to in 1
Cor. 5:6. In this respect it is used to illustrate the growth of
the kingdom of heaven both in the individual heart and in the
world (Matt. 13:33). It is a figure also of corruptness and of
perverseness of heart and life (Matt. 16:6, 11; Mark 8:15; 1
Cor. 5:7, 8).
    

85 Moby Thesaurus words for "leaven":
      abate, adjust to, agent, alter, alterant, alterative, alterer,
      assuage, bespread, besprinkle, box in, breathe, brew, catalyst,
      catalytic agent, circumscribe, color, condition, crawl with,
      creep with, decoct, diffuse, diminish, dredge, dye, entincture,
      extend throughout, ferment, fermentation, fill, flavor, hedge,
      hedge about, honeycomb, imbrue, imbue, impregnate, infiltrate,
      infuse, innovationist, innovator, instill, introducer,
      leave no void, leavening, limit, mitigate, moderate, modificator,
      modifier, modify, modulate, narrow, occupy, overrun, overspread,
      overswarm, palliate, penetrate, permeate, pervade, precursor,
      qualify, raise, reduce, regulate by, restrain, restrict,
      run through, saturate, season, set conditions, set limits, soften,
      steep, suffuse, swarm with, teem with, temper, tincture, tinge,
      transformer, transfuse, transmogrifier, yeast