Sit and fish (5)
I believe the answer is:
perch
I believe this is a double definition.
'sit' is the first definition.
(perching is a kind of sitting)
'fish' is the second definition.
(perch is a kind of fish)
'and' acts as a link.
(Other definitions for perch that I've seen before include "Roosting place" , "Freshwater game fish" , "Settle" , "(Fishy) pole where bird sits" , "Rod, pole or - -" .)