英语词源字典 - 在线词源网站

clambake (n.)[clambake 词源字典]: 1835, American English, from clam (n.) + bake (n.). By 1937 in jazz slang transferred to "an enjoyable time generally," especially "jam session."[clambake etymology, clambake origin, 英语词源]
jam (n.2): "a tight pressing between two surfaces," 1806, from jam (v.). Jazz meaning "short, free improvised passage performed by the whole band" dates from 1929, and yielded jam session (1933); but this is perhaps from jam (n.1) in sense of "something sweet, something excellent." Sense of "machine blockage" is from 1890, which probably led to the colloquial meaning "predicament, tight spot," first recorded 1914.