Strife is angry trouble between people or groups — not one short argument, but fighting that goes on. It can mean actual violence (a country with years of civil strife, where groups attack each other) or it can mean bitter conflict without any hitting at all: a family torn by strife over money, strife inside a political party. The key is that the two sides are set against each other and it does not stop quickly.

This is a formal, rather literary word. You will meet it far more in newspapers, history books, and the Bible than in speech. A news report says 'ethnic strife' or 'industrial strife' (= long fights between workers and bosses); a friend telling you about a fight at home would say 'my parents keep arguing', never 'there is strife at my house'. It is also uncountable — you say 'a lot of strife', not 'a strife' or 'three strifes'.

One place it does live in ordinary speech is the fixed phrase 'without strife' or, much more common, the set expression you meet in older writing and hymns. Australians, though, use 'strife' loosely to mean plain trouble: 'he's in strife with his boss' = he's in trouble. That use is normal there and odd elsewhere.