Dry shirt messed up attending houses (7)
I believe the answer is:
athirst
'dry' is the definition.
(I've seen this in another clue)
'shirt messed up attending houses' is the wordplay.
'messed up' indicates anagramming the letters.
'attending' becomes 'at' (e.g. at school means attending school).
'houses' is an insertion indicator.
'shirt' is an anagram of 'thirs'.
'thirs' put inside 'at' is 'ATHIRST'.
(Other definitions for athirst that I've seen before include "wanting a drink" , "Dry" , "Needing a drink (Old English)" , "having keen desire" , "Eager, avid (for)" .)