The Collaborative International Dictionary of English v.0.48:

Potation \Po*ta"tion\, n. [L. potatio, fr. potare. See
   Potable.]
   1. The act of drinking. --Jer. Taylor.
      [1913 Webster]

   2. A draught. "Potations pottle deep." --Shak.
      [1913 Webster]

   3. Drink; beverage. "Thin potations." --Shak.
      [1913 Webster]

WordNet (r) 3.0 (2006):

potation
    n 1: a serving of drink (usually alcoholic) drawn from a keg;
         "they served beer on draft" [syn: draft, draught,
         potation, tipple]
    2: the act of drinking (especially an alcoholic drink)

Moby Thesaurus II by Grady Ward, 1.0:

115 Moby Thesaurus words for "potation":
   John Barleycorn, alcohol, alcoholic beverage, alcoholic drink,
   aqua vitae, ardent spirits, bacchanal, bacchanalia, bacchanalian,
   bat, bender, beverage, binge, booze, bout, brew, bumper, bust,
   carousal, carouse, celebration, compotation, debauch, draft, dram,
   drench, drink, drinkable, drinking, drinking bout, drop, drunk,
   drunken carousal, drunkenness, frosted, frosted shake, gargle,
   grog, gulp, gulping, guzzle, guzzling, hard liquor, imbibing,
   imbibition, inebriant, intoxicant, intoxicating liquor, jag,
   jigger, jolt, lap, lapping, libation, liquid, liquor,
   little brown jug, malt, nip, nipping, orgy, peg, pop, portion,
   potable, potion, pub-crawl, pull, pulling, punch bowl, quaff,
   quaffing, round, round of drinks, rum, schnapps, shake, shot, sip,
   slipping, slurp, snifter, snort, social lubricant, soda, soda pop,
   soda water, soft drink, spirits, spot, spree, strong drink,
   strong waters, suck, sup, swig, swigging, swill, swilling,
   symposium, tasting, tear, the Demon Rum, the bottle, the cup,
   the flowing bowl, the luscious liquor, the ruddy cup, tonic, toot,
   tot, toxicant, wassail, water of life, wet