Where does “Æneide” come from?

Æneide (Middle French) comes from Latin Aeneis, from Latin Aenēas, from Latin -is, from Latin -a, from Proto-Italic -ā, from Proto-Indo-European -éh₂.

Ancestry of “Æneide”, step by step

Step	Language	Word	Meaning
1	Latin	Aeneis	—
2	Latin	Aenēas	—
3	Latin	-is	suffixed to the root of nouns in composition,...
4	Latin	-a	suffixed to the roots of verbs, forms agent...
5	Proto-Italic	-ā	Forms masculine agent nouns from prefixed or compounded bases
6	Proto-Indo-European	-éh₂	—

Every word from Proto-Indo-European -éh₂ →Every word from Latin -is →Every word from Latin -a →