Entrails
Middle English: from Old French entrailles, from medieval Latin intralia, alteration of Latin interanea ‘internal things’, based on inter ‘among’.
wiktionary
From Middle English entraille, entrailles, from Old French entrailles, from Vulgar Latin intrālia, from Latin interānea, from interāneus, from inter. Compare Spanish entraña.
etymonline
entrails (n.)
"internal parts of animal bodies," c. 1300, from Old French entrailles (12c.), from Late Latin intralia "inward parts, intestines" (8c.), from altered form of Latin interanea, noun use of neuter plural of interaneus "internal, that which is within," from inter "between, among" (from PIE *enter "between, among," comparative of root *en "in").
Latin interanea yielded Late Latin intrania, hence Italian entrango, Spanish entrañas, Old French entraigne; the alternative form that led to the Modern English word evidently is from influence of the Latin neuter plural (collective) adjective suffix -alia (French -aille).
