be quick/slow on the uptake

be (a little) slow on the uptake

To struggle to understand something. This phrase is often used as a euphemism for stupidity. Joe's a nice kid, but tutoring him is a challenge because he's a little slow on the uptake, you know? That group is slow on the uptake, so I don't know if they'll ever understand how to use this fancy new printer.
See also: on, slow, uptake

be quick on the uptake

To be able to grasp or understand something easily. She's pretty quick on the uptake, so I'm sure she'll figure out the directions you left her.
See also: on, quick, uptake

be quick (or slow) on the uptake

be quick (or slow) to understand something. informal
See also: on, quick, uptake

be ˌquick/ˌslow on the ˈuptake

(informal) understand things quickly/understand even simple things with difficulty: He’s a very good worker but he’s a bit slow on the uptake sometimes. You have to explain everything twice.
See also: on, quick, slow, uptake