Muddy place (3)
I believe the answer is:
sty
'muddy place' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for sty that I've seen before include "Pig-house" , "Pig-pen and infection on the eyelid" , "Pig pen" , "Pigpen; swelling" , "Eye ailment or pig's home" .)