type cast

To presume that an actor or actress will assume a character akin to that for which they have previously become famous. A good example is Matt Le Blanc. Having become so famous for his laid back, butt of all jokes character Joey in the tired US comedy Friends, it becomes hard to take him seriously in any other type of role.

The act of pretending you know some thing when in reality you have little to no idea on the subject and are just bs-ing