Though particular, the place is in a mess (7)
I believe the answer is:
special
'though particular' is the definition.
(I've seen this before)
'place is in a mess' is the wordplay.
'in a mess' indicates anagramming the letters.
'place'+'is'='placeis'
'placeis' with letters rearranged gives 'SPECIAL'.
'the' acts as a link.
(Other definitions for special that I've seen before include "Out of the ordinary, singular" , "Dish not on usual menu" , "Individual" , "Particular, peculiar" , "Distinctive, exceptional" .)