Australia, 1950—a traffic warden in the state of New South Wales—‘brown’ probably refers to the colour of those traffic wardens’ uniform—‘bomber’ may refer to the fact that many of those traffic wardens were originally war veterans; or perhaps to the Australian-English use of the noun ‘bomb’ for an old car
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
military slang, 1944—a medal awarded to all members of a force—especially the 1939-1945 Star, awarded to British service personnel who took part in WWII—refers to the ubiquitousness of Spam as a foodstuff
UK, 1920—an Arab man—‘Johnny’, a pet form of ‘John’, is used, with modifying word, to designate a person, especially a man, of the type, group, profession, etc., specified
a standard or device for the measurement of foolishness or folly—coined by the British author Sydney Smith (1771-1845) in ‘Second Letter to Archdeacon Singleton, Being the Third of the Cathedral Letters’ (London, 1838)
USA, 1957—the rhythm method of birth control, as permitted by the Roman Catholic Church—with allusion to the unpredictable efficacy of this contraceptive method: from ‘Vatican’, denoting the authority of the Roman Catholic Church, and ‘Russian roulette’
UK, 1974—applied jocularly to any supposed network of prominent or influential Welsh people, especially one which is strongly nationalistic—a blend of ‘Taffy’, denoting a Welshman, and ‘Mafia’
UK, 1847—a fall in value, especially a reduction in wages—one of several expressions denoting the opposite in meaning of the noun qualified by the genitive case of ‘Irishman’—for example: ‘Irishman’s promotion’ (a demotion) and ‘Irishman’s hurricane’ (nautical: a flat calm)
‘serious trouble’—USA, 1866—from the image of taking off one’s shirt before getting into a fight, and from ‘hell’ in the sense of ‘a severe reprimand’, as in ‘to give someone hell’
used of a person who is frozen with fright or surprise, or is trying to flee, as a result of suddenly becoming the focus of attention—alludes to the habit of deer and rabbits of stopping still when dazzled by the headlights of a motor vehicle, or of running away within the headlight beam