infantry
Concise Oxford English Dictionary © 2008 Oxford University Press:
infantry/ˈɪnfəntri/
▶noun foot soldiers collectively.
– derivatives
infantryman noun (pl. infantrymen).
infantryman noun (pl. infantrymen).
– origin C16: from Fr. infanterie, from Ital. infanteria, from infante ‘youth, infantryman’, from L. infant- (see infant).
'infantry' also found in these Oxford entries:

