third-rate actor; ham actor
Derogatory term for an actor of very low skill or status. 三文 (three mon) implies something cheap or worthless.
He's a third-rate actor, but for some reason he's popular.
三文 means 'three mon' (a small amount of money) and is used as a prefix meaning cheap, worthless, or third-rate. 三文役者 is a compound using this prefix.
役者 is a general word for actor or performer. 三文役者 specifically denotes a low-quality actor.
Compound of 三文 (three mon, a trifling sum) and 役者 (actor). The expression likens a poor actor to something worth only a few coins.