eclosion

noun

eclo·​sion i-ˈklō-zhən 

of an insect

: the act of emerging from the pupal case or hatching from the egg

Word History

Etymology

borrowed from French éclosion, from éclos-, variant stem of éclore "to hatch (from an egg), emerge (from a cocoon)" (going back to Old French esclore, going back to Vulgar Latin *exclaudere, re-formation of Latin exclūdere "to bring out from its container, hatch from an egg") + -ion -ion — more at exclude

First Known Use

circa 1889, in the meaning defined above