Infantry

Infantry (i·nfăntri). Also 6-7 ·terie, ery, 7 -trie, (ree). [a. F. infanterie, ad. It (Sp., Pg.) infanteria foot soldiery, f. infante a youth, foot-solder:—L. infāntent INFANT sb.¹ For the development of the It. infante cf. the acopopated form fante 'a man or woman servant or attendant; also a footman or soldier serving on foot; also the knave or varlet at cards' (Florio); cf. also the history of footman, groom, knave, knight, lad, etc. By Sylvester stressed (infa·nt̀ĕri).

1. The body of foot-soldiers; foot-soldiers collectively; that part of an army that consists of men who march and manœuvre on foot and are armed with small arms, now a rifle.

— The Oxford English Dictionary
© Oxford University Press

THIS CONFLICT between infantry and infantry... was... the crucial element of the battle — a statement which can be made with fair safety of almost every battle fought in the period between the eclipse of the armoured horseman in the fourteenth century and the rise of the armored fighting vehicle in the twentieth... Since infantry was (and is) the only force with which ground could (and can) be held... it could never be withdrawn from ground whose possession was held vital simply to avert loss of life.