From Latin 'civis' (citizen), from PIE *key- (to settle) — civilization is etymologically the state of settled life.
To bring to a more advanced stage of social development; to educate or refine someone.
From French civiliser, from Latin civilis (of or pertaining to citizens, civil), from civis (citizen). The PIE root is *kei- (to lie down, to settle, to be at home) — citizens are those who have settled, those who make a home in one place. The semantic chain runs: settling down → home-dwellers → city-dwellers → citizens → civilised
The word 'civilize' shares its deepest root with 'home.' PIE *ḱey- (to settle, to lie down) produced both Latin 'cīvis' (a settled person — a citizen) and Germanic 'hām' (a settlement — home). Civilization and home are the same concept at the PIE level: both begin with the act of settling down.