play dumb

(verb) to pretend to be very stupid

Example Sentences:

A: Do you like your new roommate?
B: Not really, I feel like he’s very smart but always plays dumb.
A: Why do you say that?
B: He acts unintelligent but he has a Masters Degree. He seems so stupid, but he’s not!

The beautiful woman played dumb, but was actually very smart.

The young boy was playing dumb because he didn’t want his classmates to insult him.

From the Blogs:

Health care mobs = Swift Boat Vets. And the press plays dumb, again

Media:

Similar idioms:

1. not playing with a full deck
2. add insult to injury
3. fresh off the boat
4. dead from the neck up