The word has two ways of being true of someone, and usually both are. It can point at where a person is from — Croatia, a country on the eastern side of the Adriatic Sea — and it can point at the people they belong to, which is why Croats also live in countries next to Croatia and in communities far from it. It is countable, so it behaves like any other word for a person: a Croat, two Croats, many Croats. It always takes a capital C.

Language names behave differently from names for people: this one is uncountable, takes no a, and no plural — you speak Croat, you read Croat. The learner dictionary adds that it is one form of Serbo-Croat, the name once used for the closely related speech of several neighbouring countries. One thing worth knowing before you use it: the source marks this way of naming the language uncommon, and most people today say Croatian instead, so you are more likely to read Croat than to need to say it.