Hombre means a man. English borrowed it straight from Spanish, where it is the ordinary word for “man” or “human being.” In English it is informal, and it often hints that the man is tough, strong, or a bit of a cowboy. You hear it in American speech, especially in the southwest and in Western films: a tough hombre, a bad hombre. Though actually, in Spanish there is no cowboy flavour at all — it is as plain as man. In English that cowboy flavour is usually the point. Friends may say “Hey, hombre” as a jokey way to address a man. It can sound playful or old-fashioned; in some mouths it can sound unkind. It is not a word for formal writing.