Unarmed means carrying no weapon — no gun, no knife, nothing to fight with. It is a plain, factual word, but it almost never appears in a neutral situation, and that is the thing to understand. You meet it in news reports and courtrooms, where it is doing moral work: "police shot an unarmed man" is a sentence built so that the missing weapon is the whole point. Saying someone was unarmed is a way of saying they could not have been a real danger, so whatever was done to them was too much. That is why the word feels heavy even though its meaning is simple. Two other places you will see it. First, the military phrase unarmed combat — fighting with your hands and body only, the training soldiers and police do; here it is a normal technical term with no emotional weight. Second, it describes things, not just people: an unarmed ship, an unarmed drone, an unarmed guard at a building. English also has a set phrase for the opposite of prepared: to "go in unarmed" can jokingly mean going into a meeting or an exam with nothing ready.