"intoxicating liquor made by malt fermentation," Old English ealu "ale, beer," from Proto-Germanic *aluth- (source also of Old Saxon alo, Old Norse öl), which is of uncertain origin. Perhaps from a PIE root meaning "bitter" (source also of Latin alumen "alum"), or from PIE *alu-t "ale," from root *alu-, which has connotations of "sorcery, magic, possession, and intoxication" [Watkins]. The word was borrowed from Germanic into Lithuanian (alus) and Old Church Slavonic (olu).
In the fifteenth century, and until the seventeenth, ale stood for the unhopped fermented malt liquor which had long been the native drink of these islands. Beer was the hopped malt liquor introduced from the Low Countries in the fifteenth century and popular first of all in the towns. By the eighteenth century, however, all malt liquor was hopped and there had been a silent mutation in the meaning of the two terms. For a time the terms became synonymous, in fact, but local habits of nomenclature still continued to perpetuate what had been a real difference: 'beer' was the malt liquor which tended to be found in towns, 'ale' was the term in general use in the country districts. [Peter Mathias, "The Brewing Industry in England," Cambridge University Press, 1959]
Meaning "festival or merry-meeting at which much ale was drunk" was in Old English (see bridal).
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] 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 zymē "leaven."
Spanish cerveza is from Latin cervesia "beer." 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.
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]