Breeding

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Old English brēdan ‘produce (offspring), bear (a child)’, of Germanic origin; related to German brüten, also to brood.

wiktionary

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From Middle English breedyng, bredynge(“gestation, incubation, propagation, hatching; engineering, formation, development, growth”), equivalent to breed +‎ -ing.

From Middle English bredyng, bredynge, from Old English *brēdende, from Proto-Germanic *brōdijandz, present participle of Proto-Germanic *brōdijaną(“to brood; breed”), equivalent to breed +‎ -ing.

etymonline

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breeding (n.)

early 14c., "hatching, incubation; act of generating or producing;" late 14c., "formation, development, growth;" verbal noun from breed (v.). Meaning "manners, deportment in social life" is from 1590s (commonly short for good breeding), from the notion of "upbringing."