beer (n.)
alcoholic drink made from grain, generally barley, infused with hops and boiled and fermented, Old English beor "strong drink, beer, mead," cognate with Old Frisian biar, Middle Dutch and Dutch bier, Old High German bior, German Bier; a West Germanic word of much-disputed and ambiguous origin.

Probably a 6c. West Germanic monastic borrowing of Vulgar Latin biber "a drink, beverage" (from Latin infinitive bibere "to drink," from PIE root *po(i)- "to drink"). Another suggestion is that it comes from Proto-Germanic *beuwoz-, from *beuwo- "barley." The native Germanic word for the beverage was the one that yielded ale (q.v.). "The word occurs in OE., but its use is rare, except in poetry, and it seems to have become common only in the 16th c. as the name of a hopped malt liquor." [OED]
Beer was a common drink among most of the European peoples, as well as in Egypt and Mesopotamia, but was known to the Greeks and Romans only as an exotic product. [Buck]
They did have words for it, however. Greek brytos, used in reference to Thracian or Phrygian brews, was related to Old English breowan "brew;" Latin zythum is from Greek zythos, first used of Egyptian beer and treated as an Egyptian word but perhaps truly Greek and related to zyme "leaven."

Spanish cerveza is from Latin cervesia "beer," which is perhaps related to Latin cremor "thick broth." Old Church Slavonic pivo, source of the general Slavic word for "beer," is originally "a drink" (compare Old Church Slavonic piti "drink"). French bière is a 16c. borrowing from German. U.S. slang beer goggles, through which every potential romantic partner looks desirable, is from 1986.