Spawn
late Middle English: shortening of Anglo-Norman French espaundre ‘to shed roe’, variant of Old French espandre ‘pour out’, from Latin expandere ‘expand’.
wiktionary
Recorded since 1413; from Middle English spawnen, from Anglo-Norman espaundre, from Old French espandre, from Latin expandere(“stretch out; spread out”, verb). Doublet of expand. Compare also Middle English spalden, spolden, spawden(“to cut open (a fish)”).
From Middle English spawne, from the verb (see above).
etymonline
spawn (v.)
c. 1400, intransitive, from Anglo-French espaundre, Old French espandre "to spread out, pour out, scatter, strew, spawn (of fish)" (Modern French épandre), from Latin expandere "to spread out, unfold, expand," from ex "out" (see ex-) + pandere "to spread, stretch" (from nasalized form of PIE root *pete- "to spread"). The notion is of a "spreading out" of fish eggs released in water. The transitive meaning "to engender, give rise to" is attested from 1590s. Related: Spawned; spawning.
spawn (n.)
late 15c., "fish eggs," from spawn (v.); figurative sense of "brood, offspring," and, insultingly, of persons, is from 1580s.