infantry (n.) Look up infantry at Dictionary.com
1570s, from French infantrie, infanterie (16c.), from older Italian or Spanish infanteria "foot soldiers, force composed of those too inexperienced or low in rank to be cavalry," a collective noun 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."