She 'played/acted dumb' [=pretended to know or understand less than she really did] so we would assign her the easier tasks.
She thinks television is contributing to the 'dumbing down' of America.
Cutting training programs will 'dumb down' the American workforce.
(..) Yeah? Yeah, you got something to say Murphy? Vallon's our case. You got two years without no arrests, no nothin. He's got to be dumb or dirty. You got something on us? Or is this personal? No, it's nothin personal. Although I don't like you as a person. Okay, you two, out. (..)2014 RoboCop