Source : Webster's Revised Unabridged Dictionary (1913)

Allay \Al*lay"\, v. t. [imp. & p. p. {Allayed}; p. pr. & vb. n.
   {Allaying}.] [OE. alaien, aleggen, to lay down, put down,
   humble, put an end to, AS. [=a]lecgan; [=a]- (cf. Goth. us-,
   G. er-, orig. meaning out) + lecgan to lay; but confused with
   old forms of allege, alloy, alegge. See {Lay}.]
   1. To make quiet or put at rest; to pacify or appease; to
      quell; to calm; as, to allay popular excitement; to allay
      the tumult of the passions.

   2. To alleviate; to abate; to mitigate; as, to allay the
      severity of affliction or the bitterness of adversity.

            It would allay the burning quality of that fell
            poison.                               --Shak.

   Syn: To alleviate; check; repress; assuage; appease; abate;
        subdue; destroy; compose; soothe; calm; quiet. See
        {Alleviate}.

Allay \Al*lay"\, v. t.
   To diminish in strength; to abate; to subside. ``When the
   rage allays.'' --Shak.

Allay \Al*lay"\, n.
   Alloy. [Obs.] --Chaucer.

Allay \Al*lay"\, n.
   Alleviation; abatement; check. [Obs.]

Allay \Al*lay"\, v. t.
   To mix (metals); to mix with a baser metal; to alloy; to
   deteriorate. [Archaic] --Fuller.

Source : WordNet®

allay
     v 1: lessen the intensity of or calm; "The news eased my
          conscience"; "still the fears" [syn: {still}, {relieve},
           {ease}]
     2: satisfy (thirst); "The cold water quenched his thirst" [syn:
         {quench}, {slake}, {assuage}]