USA, 1974—a moment of sudden realisation, enlightenment or inspiration—alludes to the representation of an illuminated lightbulb above a character’s head in a cartoon or comic strip, indicating that this character has had an idea
USA, 1978—to commit suicide; to demonstrate unquestioning obedience or loyalty—alludes to a mass suicide, in 1978, by members of the Peoples’ Temple in Jonestown, Guyana, who drank a cyanide-laced drink thought to be similar to Kool-Aid
USA, 1918—a mechanic—since the 17th century, ‘monkey’ has been used (frequently with modifying word indicating the occupation concerned) to denote a person engaged in a trade or profession
USA—‘squillion’ (1879): an extremely large but unspecified number, quantity or amount; arbitrary and humorous alteration of ‘million’, ‘billion’, etc.—‘squillionaire’ (1895): a person who has an extremely large but unspecified amount of money
UK, 1899—derogatory—a foreigner; a personification of foreign people—‘Johnny’ is used with modifying word to designate a person of the type, group, profession, etc., specified