What is Bitman?
1.
A actor who regularly plays bit parts. A bit part is a supporting acting role with at least one line of dialogue. In television, bit parts are referred to as under sixes (fewer than six spoken lines). Unlike extras, who do not speak any lines at all; actors in bit parts are typically listed in the credits. An exception to this practice is the cameo appearance, wherein a well-known actor (or other celebrity) appears in a bit part; it is not uncommon for such appearances to be uncredited.
He's not a great actor, that's why he will always remain a bitman.