The Collaborative International Dictionary of English v.0.48:

Imbibe \Im*bibe"\, v. t. [imp. & p. p. Imbibed; p. pr. & vb.
   n. Imbibing.] [L. imbibere; pref. im- in + bibere to drink:
   cf. F. imbiber. Cf. Bib, Imbue, Potable.]
   1. To drink in; to absorb; to soak up; to suck or take in; to
      receive as by drinking; as, a person imbibes drink, or a
      sponge imbibes moisture.
      [1913 Webster]

   2. To receive or absorb into the mind and retain; as, to
      imbibe principles; to imbibe errors.
      [1913 Webster]

   3. To saturate; to imbue. [Obs.] "Earth, imbibed with . . .
      acid." --Sir I. Newton.
      [1913 Webster]

WordNet (r) 3.0 (2006):

imbibe
    v 1: take in, also metaphorically; "The sponge absorbs water
         well"; "She drew strength from the minister's words" [syn:
         absorb, suck, imbibe, soak up, sop up, suck up,
         draw, take in, take up]
    2: take (gas, light or heat) into a solution [syn: assimilate,
       imbibe]
    3: take in liquids; "The patient must drink several liters each
       day"; "The children like to drink soda" [syn: drink,
       imbibe]
    4: receive into the mind and retain; "Imbibe ethical principles"

Moby Thesaurus II by Grady Ward, 1.0:

75 Moby Thesaurus words for "imbibe":
   absorb, adsorb, assimilate, bib, blot, blot up, booze, chemisorb,
   chemosorb, devour, digest, drain the cup, dram, drink,
   drink bottoms-up, drink deep, drink hard, drink in, drink off,
   drink to, drink up, eat, engorge, engross, engulf, filter in,
   follow strong drink, gargle, gobble, grog, gulp, gulp down, guzzle,
   incorporate, infiltrate, ingest, ingurgitate, knock back, lap,
   lap up, liquor up, nip, osmose, percolate in, pledge, pull, quaff,
   seep in, sip, slurp up, soak, soak in, soak up, sorb, sponge, suck,
   suck in, suckle, sup, swallow, swig, swill, swill down, swill up,
   take in, take up, tank up, tipple, toast, tope, toss, toss down,
   toss off, wash down, wolf down