Somewhere for cat to sit and drink (3)
I believe the answer is:
lap
'drink' is the definition.
(to lap is to drink up)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for lap that I've seen before include "Sports circuit" , "Once around the course" , "place for small computer?" , "Circuit of racetrack" , "Drink; lick" .)