infantry (n.)youdaoicibaDictYouDict[infantry 词源字典]
1570s, from French infantrie, from older Italian, Spanish infanteria "foot soldiers, force composed of those too inexperienced or low in rank for cavalry," from infante "foot soldier," originally "a youth," from Latin infantem (see infant). Meaning "infants collectively" is recorded from 1610s. A Middle English (c. 1200) word for "foot-soldiers" was going-folc, literally "going-folk."[infantry etymology, infantry origin, 英语词源]