beer (n.) Look up beer at
Old English beor "strong drink, beer, mead," a word of much-disputed and ambiguous origin, cognate with Old Frisian biar, Middle Dutch and Dutch bier, Old High German bior, German Bier.

Probably a 6c. West Germanic monastic borrowing of Vulgar Latin biber "a drink, beverage" (from Latin infinitive bibere "to drink;" see imbibe). 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.).
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." French bière is from Germanic. Spanish cerveza is from Latin cervesia "beer," 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.