Tasty? No thanks _ it's dirty! (3)
I believe the answer is:
sty
'it's dirty' is the definition.
I can't tell whether this definition defines the answer.
'tasty? no thanks' is the wordplay.
'no' is a deletion indicator.
'thanks' becomes 'ta' (UK informal version of 'thank you').
'tasty' with 'ta' taken away is 'STY'.
Can you help me to learn more?
(Other definitions for sty that I've seen before include "Piggery" , "Sore on eyelid" , "Hog house" , "Pig's enclosure" , "Filthy place" .)