A snare is a trap for catching birds or small animals. It consists of a loop of wire or rope which pulls tight around the animal.

If you describe a situation as a snare, you mean that it is a trap from which it is difficult to escape.

If someone snares an animal, they catch it using a snare.

If someone is snared, they are caught in a trap.

If someone snares something, they get it in a clever way, perhaps by deceiving people.