Where does “ciné-” come from?

ciné- (French) comes from Ancient Greek κῑνέω, from Proto-Indo-European ḱey- — to be lying down; to settle.

Ancestry of “ciné-”, step by step

Step	Language	Word	Meaning
1	Ancient Greek	κῑνέω	set in motion, move; to move, to stir; I move
2	Proto-Indo-European	ḱey-	to be lying down; to settle