Squad
mid 17th century: shortening of French escouade, variant of escadre, from Italian squadra ‘square’.
wiktionary
From French escouade, from Italian squadra(“square”) (whence also French escadre).
Uncertain. Compare squick(“disgust”), squalid(“dirty”) with similar initial sounds.
etymonline
squad (n.)
1640s, "small number of military men detailed for some purpose," from French esquade, from French escadre, from Spanish escuadra or Italian squadra "battalion," literally "square," from Vulgar Latin *exquadra "to square," from Latin ex "out" (see ex-) + quadrare "make square," from quadrus "a square" (from PIE root *kwetwer- "four"). Before the widespread use of of automatic weapons, infantry troops tended to fight in a square formation to repel cavalry or superior forces. Extended to sports 1902, police work 1905.
