Tandem
来自Big Physics
late 18th century: humorously from Latin, literally ‘at length’.
wiktionary
From Latin tandem(“(of time) at length, at last”). In English, applied humorously (by someone who knew Latin) to two horses harnessed "at length" (i.e., in a single line) instead of side-by-side.
etymonline
tandem (n.)
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.
