Source : Webster's Revised Unabridged Dictionary (1913)

Slake \Slake\, v. t. [imp. & p. p. {Slaked}; p. pr. & vb. n.
   {Slaking}.] [OE. slaken to render slack, to slake, AS.
   sleacian, fr. sleac slack. See {Slack}, v. & a.]
   1. To allay; to quench; to extinguish; as, to slake thirst.
      ``And slake the heavenly fire.'' --Spenser.

            It could not slake mine ire nor ease my heart.
                                                  --Shak.

   2. To mix with water, so that a true chemical combination
      shall take place; to slack; as, to slake lime.

Slake \Slake\, v. i.
   1. To go out; to become extinct. ``His flame did slake.''
      --Sir T. Browne.

   2. To abate; to become less decided. [R.] --Shak.

   3. To slacken; to become relaxed. ``When the body's strongest
      sinews slake.'' [R.] --Sir J. Davies.

   4. To become mixed with water, so that a true chemical
      combination takes place; as, the lime slakes.

   {Slake trough}, a trough containing water in which a
      blacksmith cools a forging or tool.

Source : WordNet®

slake
     v 1: satisfy (thirst); "The cold water quenched his thirst" [syn:
           {quench}, {allay}, {assuage}]
     2: make less active or intense [syn: {abate}, {slack}]
     3: cause to heat and crumble by treatment with water; "slack
        lime" [syn: {slack}]