aleyoudaoicibaDictYouDict[ale 词源字典]
ale: [OE] Old English ealu ‘ale’ goes back to a Germanic root *aluth-, which also produced Old Norse öl (Scandinavian languages still use alerelated words, whereas other Germanic languages now only use beer-related words; English is the only one to retain both). Going beyond Germanic in time takes us back to the word’s ultimate Indo-European source, a base meaning ‘bitter’ which is also represented in alum and aluminium. Ale and beer seem to have been virtually synonymous to the Anglo- Saxons; various distinctions in usage have developed over the centuries, such as that ale is made without hops, and is heavier (or some would say lighter) than beer, but most of the differences have depended on local usage.

The word bridal is intimately connected with ale. Nowadays used as an adjective, and therefore subconsciously associated with other adjectives ending in -al, in Old English it was a noun, literally ‘bride ale’, that is, a beer-drinking session to celebrate a marriage.
[ale etymology, ale origin, 英语词源]
ale (n.)youdaoicibaDictYouDict
Old English ealu "ale, beer," from Proto-Germanic *aluth- (cognates: Old Saxon alo, Old Norse öl), perhaps from PIE root meaning "bitter" (cognates: Latin alumen "alum"), or from PIE *alu-t "ale," from root *alu-, which has connotations of "sorcery, magic, possession, intoxication." 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 Countires 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).