factor (n.)youdaoicibaDictYouDict[factor 词源字典]
early 15c., "commercial agent, deputy, one who buys or sells for another," from Middle French facteur "agent, representative" (Old French factor, faitor "doer, author, creator"), from Latin factor "doer, maker, performer," in Medieval Latin, "agent," agent noun from past participle stem of facere "to do" (see factitious). In commerce, especially "a commission merchant." Mathematical sense is from 1670s. Sense of "circumstance producing a result" is attested by 1816, from the mathematical sense.[factor etymology, factor origin, 英语词源]
grocer (n.)youdaoicibaDictYouDict
early 15c. (mid-13c. as a surname), "wholesale dealer, one who buys and sells in gross," corrupted spelling of Anglo-French grosser, Old French grossier, from Medieval Latin grossarius "wholesaler," literally "dealer in quantity" (source also of Spanish grosero, Italian grosseiro), from Late Latin grossus "coarse (of food), great, gross" (see gross (adj.)). Sense of "a merchant selling individual items of food" is 16c.; in Middle English this was a spicer.
mot (n.)youdaoicibaDictYouDict
"a witty saying," 1580s, from French mot (12c.) "remark, short speech," literally "word," cognate of Italian motto, from Latin mutum "grunt, murmur" (see mutter). Mot juste (1912) is French, literally "exact word," the precisely appropriate expression in some situation.
The mot juste is an expression which readers would like to buy of writers who use it, as one buys one's neighbour's bantam cock for the sake of hearing its voice no more. [Fowler]