Poltroon is an old-fashioned word for a type of person that exists in every time period: a coward. If you behave in a way that shows no courage or confidence, you're acting like a poltroon. In movies, the villains are often poltroons who are sneaky and devious instead of brave and straightforward. A hero is the opposite of a poltroon. Poltroons can be described as craven and abject, but most of all, cowardly.