civ

The root civ comes from one of the most important ideas in Roman thought: the civis, the citizen. A civis was not just a person who lived somewhere — he was a free member of the community with rights and duties. The collective noun for all the citizens together was civitas: the body of citizens, and by extension the city-state they formed and the citizenship they shared. So from the start there are two layers: civis (one citizen) and civitas (the whole community of citizens). Almost every English word in this family grows out of one of those two.

From civitas — the community — comes the most everyday word of all. Civitas passed through Old French cité into English as city: originally the citizen-community itself, then the place where that community lived. The same civitas gave us citizen (Old French citeain) — literally a member of the cité, a city-dweller, then a full legal member of a state. And citadel comes from Italian cittadella, a 'little city' — the fortified inner stronghold that protected the city-community.

Important warning about the spelling cit-: the cit- in city, citizen, and citadel comes from civitas (city/community), where the v simply softened away over centuries of French. It has nothing to do with the other English root cit that comes from Latin citāre 'to summon, set in motion' (which gives cite, excite, recite, incite). Same four letters, completely unrelated origins. If the word is about a city or its people, it is the civ family; if it is about calling or stirring up, it is the citāre family.

From civis and the adjective civilis ('of citizens') come the more abstract words. Civic means 'of the citizen and his city' — civic duty, civic center. Civil is the richest member: it first meant 'of citizens' (as opposed to military or religious), giving civil law, civil rights, civil war, civil servant. But because citizens living together were expected to behave decently toward one another, civil also drifted into meaning 'polite, courteous' — and from that sense come civility (citizen-like good manners) and the formal opposite, incivility. A civilian is a 'civil' person in the first sense: an ordinary citizen, specifically one who is not a soldier or police officer.

Finally the grand abstractions. To civilize is to bring people into the settled, law-governed life of a civitas — to turn them from a 'wild' state into citizens. And civilization is the end result: the whole condition of living in an organized society of citizens, with cities, laws and culture. Notice the chain hidden inside that long word: civis → civilis → civilize → civilization. The biggest word in the family is just the citizen idea, scaled all the way up to an entire society.