Messy place (3)
I believe the answer is:
sty
'messy place' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for sty that I've seen before include "Pig house" , "Porcine pen" , "Hog house" , "Pig-pen and eye infection" , "Pig's enclosure" .)