of a person or thing: irretrievably defunct or out of date—UK, 1905—perhaps originally in allusion to ‘Diplodocus Carnegii’, named after Andrew Carnegie, who, that year, presented the skeleton of that diplodocus to the Natural History Museum of London
a rich and important man—USA, 1958, as ‘Charlie Potatoes’—UK, 1995, as ‘Charlie Big Potatoes’— ‘Charlie’: generic term for a man—‘potatoes’: perhaps slang for ‘money’, ‘dollars’
bag-in-box wine—USA, 2006—a blend of ‘cardboard’ (in reference to the outer packaging of bag-in-box wine) and of ‘Bordeaux’ (in reference to the wine made in the Bordeaux region of France)
having the lips tightly closed—hence, figuratively: uncommunicative, determinedly reticent—USA, 1942—refers to the noun ‘zip’, designating a fastening device
an easy target, i.e., a person who, or thing that, is defenceless against an attack or other danger—first used in 1936 & 1937 by the Canadian journalist Gordon Sinclair
literally (UK, 1803): of a firearm: equipped with a hair trigger—hence, figuratively (Ireland, 1853): reacting immediately to the slightest provocation or cause