Squadron

google

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mid 16th century (originally denoting a group of soldiers in square formation): from Italian squadrone, from squadra ‘square’.

wiktionary

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From Italian squadrone. See squad.

etymonline

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squadron (n.)

1560s, from Italian squadrone, augmentative of squadra "battalion," literally "square" (see squad). As a division of a fleet, from 1580s, of an air force, 1912.