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.).
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." French bière is from Germanic. Spanish cerveza is from Latin cervesia "beer," perhaps related to Latin cremor "thick broth."