Origins
The word 'civilize' entered English in the early seventeenth century from French 'civiliser,' which was derived from Latin 'cīvilis' (of or pertaining to citizens, civil, polite). The Latin adjective comes from 'cīvis' (citizen), which traces to the PIE root *ḱey-, meaning 'to lie down,' 'to settle,' or 'home.' At its deepest level, civilization is about settlement — the transition from nomadic life to fixed habitation, from wandering to dwelling.
The PIE root *ḱey- generated two parallel but independent word families in English. Through Latin 'cīvis': 'civil' (pertaining to citizens), 'civilization,' 'civilize,' 'citizen' (from Old French 'citeain,' from Latin 'cīvitātem'), 'city' (from Old French 'cité,' from Latin 'cīvitās,' a community of citizens), and 'civic' (from Latin 'cīvicus'). Through the Germanic branch: 'home' (from Old English 'hām,' a dwelling, a settlement), which is the native English reflex of the same PIE root. The connection is not obvious — 'civil' and 'home' look nothing alike — but the sound correspondences are regular: PIE *ḱ became 'c' (/k/) in Latin but 'h' in Germanic.
The concept encoded in the etymology is that a citizen is a 'settler' — someone who has put down roots, who belongs to a place. This is opposed to the nomad, the wanderer, the barbarian (Greek 'bárbaros,' originally meaning 'one who speaks unintelligibly' — a foreigner). The Greeks and Romans defined civilization against its perceived opposite: the unsettled, the uncultivated, the foreign.
Development
The verb 'civilize' was coined in the context of Renaissance and early modern European thought about cultural development. Montaigne used 'civiliser' in sixteenth-century French. The English adoption reflects the Enlightenment project of understanding human societies as progressing through stages — from savagery through barbarism to civilization. This framework, formalized by thinkers like Adam Ferguson, Lewis Henry Morgan, and (problematically) colonial administrators, carried the assumption that European society represented the pinnacle of development and that other societies needed to be 'civilized.'
The word's colonial baggage is significant. 'Civilizing mission' (French 'mission civilisatrice') was the phrase used to justify European imperial expansion in Africa and Asia during the nineteenth and twentieth centuries. The argument was that colonized peoples needed to be brought to a higher state of development — 'civilized' — by European powers. This usage has been extensively critiqued by postcolonial scholars, who point out that the word encodes a hierarchy of cultures that privileges the colonizer.
The derivative 'civilization' first appeared in French in 1756 and in English by 1772. Its meaning oscillates between a neutral descriptive term (a complex society with writing, cities, and institutional governance) and a normative evaluative term (a society that has achieved refinement and moral development). The ambiguity is baked into the word: to call something a 'civilization' is simultaneously to describe it and to evaluate it.
Latin Roots
Modern English uses the 'civil-' family in many contexts stripped of these grand historical associations. 'Civil rights' (the rights of citizens), 'civil engineering' (engineering for civilian purposes), 'civil servant' (a government employee), 'civil war' (war between citizens of the same country), and 'civilian' (a non-military person) all use 'civil' in its straightforward Latin sense: pertaining to citizens and the community.