cavalieryoudaoicibaDictYouDict[cavalier 词源字典]
cavalier: [16] Etymologically, a cavalier is a ‘horseman’. The word comes via French cavalier from Italian cavaliere, which was derived from Latin caballus ‘horse’, either directly or via late Latin caballārius ‘horseman, rider’. From the beginning in English its connotations were not those of any old horserider, but of a mounted soldier or even a knight, and before the end of the 16th century the more general meaning ‘courtly gentleman’ was establishing itself.

This led in the mid-17th century to its being applied on the one hand to the supporters of Charles I, and on the other as an adjective meaning ‘disdainful’. Italian cavaliere was also the source of cavalleria ‘body of horsesoldiers’, which was borrowed into English in the 16th century, via French cavallerie, as cavalry. (The parallel form routed directly through French rather than via Italian was chivalry.)
=> cavalry, chivalry[cavalier etymology, cavalier origin, 英语词源]
cavalier (n.)youdaoicibaDictYouDict
1580s, from Italian cavalliere "mounted soldier, knight; gentleman serving as a lady's escort," from Late Latin caballarius "horseman," from Vulgar Latin caballus, the common Vulgar Latin word for "horse" (and source of Italian cavallo, French cheval, Spanish caballo, Irish capall, Welsh ceffyl), displacing Latin equus (see equine).

Sense advanced in 17c. to "knight," then "courtly gentleman" (but also, pejoratively, "swaggerer"), which led to the adjectival senses, especially "disdainful" (1650s). Meaning "Royalist adherent of Charles I" is from 1641. Meaning "one who devotes himself solely to attendance on a lady" is from 1817, roughly translating Italian cavaliere-servente. In classical Latin caballus was "work horse, pack horse," sometimes, disdainfully, "hack, nag." "Not a native Lat. word (as the second -a- would show), though the source of the borrowing is uncertain" [Tucker]. Perhaps from some Balkan or Anatolian language, and meaning, originally, "gelding." The same source is thought to have yielded Old Church Slavonic kobyla.
cavalier (adj.)youdaoicibaDictYouDict
"disdainful," 1650s, from cavalier (n.). Earlier it meant "gallant" (1640s). Related: Cavalierly.