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.
(..) I figured, after we married, I'd have to stage a little accident for Elsa. Hans. No, stop. But then she doomed herself, and you were ...dumb enough to go after her. Please. All that's left now is to kill Elsa and bring back summer. You're no match for Elsa. No, you're no match for Elsa. (..)2013 Frozen
(..) Where did you get this? Bodega. Way across town. In, out, like, bam. Went smooth as silk, yo. What, nobody saw you? What about witnesses, dumb-ass? We roll like the breeze, for real. All we did, we just walked in all smooth-like. - Nobody even noticed. - Nobody noticed? (..)2009 TvShow: Breaking Bad Title: Peekaboo Season: 2 Episode 6
(..) makes me feels like an idiot, steals my double barrow and says I'm the one that can't be trusted. Nice going genius. You're the one that gave her the gun. Those guys were dumb. - Avoid the vanity mirror. - Relax ok, I just passed for a zombie. - What I'd give for a show... Just get the rule going. (..)2009 Zombieland