What defines someone as a loser?

1 : a person or thing that loses especially consistently The team had a reputation for being a loser year after year. 2 : a person who is incompetent or unable to succeed Dont waste your time on that loser.

Is Loser a cuss word?

A person who loses; one who fails to win or thrive. (derogatory) A contemptible or unfashionable person. That person is a loser!