noun, masculine/ɑ̃.se.fal/plural: encéphales
encéphale is masculine in French.
encephalon, brain
Related: encéphalique, encéphalite
Learned borrowing from Ancient Greek ἐγκέφαλος (enképhalos, “within the head”), from ἐν (en, “in”) + κεφαλή (kephalḗ, “head”).