Seat for blind pirate (3)
I believe the answer is:
'seat' is the definition.
(pew is a kind of seat)
I don't understand the rest of the clue.
(Other definitions for pew that I've seen before include "Part of flock sitting here" , "Bench-like seat in a church" , "Where some of the flock rest" , "Long church seat" , "Long bench in a church" .)