costeryoudaoicibaDictYouDict[coster 词源字典]
coster: [19] Coster is short for costermonger, a term dating from the 16th century. Since the 19th century, and perhaps before, it has been a general term in Britain, and particularly in London, for a street trader with a barrow or stall, but further back in time it meant ‘fruiterer’, and originally, more specifically still, a ‘seller of apples’. The first element, coster, was an alteration of costard, a word of Anglo-Norman origin for a type of large apple.

This was derived from coste ‘rib’ (a descendant of Latin costa, source of English coast), and the costard was apparently so called because of its prominent ‘ribs’. (Monger ‘dealer’ [OE], now used in English only in compounds, comes from a prehistoric Germanic *manggōjan, a borrowing from Latin mangō ‘dealer’.)
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