tandemyoudaoicibaDictYouDict[tandem 词源字典]
tandem: [18] Latin tandem meant ‘eventually, at length’. Its use for ‘acting conjointly’ arose from an 18th-century play on words, in which ‘at length’ was jocularly interpreted as ‘lengthwise, in a straight line’, and the word was applied to a ‘carriage drawn by two horses one behind the other in a straight line’. In the 1880s it was transferred to a ‘bicycle with two seats, one behind the other’. Its more general modern use, for ‘acting together’, dates from the early 20th century.
[tandem etymology, tandem origin, 英语词源]
tandem (n.)youdaoicibaDictYouDict
1785, "carriage pulled by horses harnessed one behind the other" (instead of side-by-side), jocular use of Latin tandem "at length (of time), at last, so much," from tam "so" (from PIE *tam-, adverbial form of demonstrative pronoun root *-to-; see -th (1)) + demonstrative suffix -dem. "Probably first in university use" [Century Dictionary]. Transferred by 1884 to bicycles with two seats. In English as an adverb from 1795; as an adjective from 1801.