slow on the uptake

Stupid or dimwitted; slow or unable to understand something. Jim's a little slow on the uptake, so you might want to check that he's following your instructions. I was always a bit slow on the uptake as a kid, so school was never my favorite place to be.

slow on the uptake

If someone is slow on the uptake, they take a long time to understand or realise things. It's not like you to be slow on the uptake, Grace. He is quite anxious sometimes, and a bit slow on the uptake. Note: You can say that someone is quick on the uptake to mean that they understand or realise things very quickly. He is quick on the uptake and knows exactly which points to pick up.