Dubious citizen turning up in peculiar places (9)
I believe the answer is:
sceptical
'dubious' is the definition.
(I've seen this before)
'citizen turning up in peculiar places' is the wordplay.
'citizen' becomes 'cit' (old-fashioned abbreviation for citizen).
'turning up' says the letters should be written backwards.
'in' means one lot of letters goes inside another.
'peculiar' indicates anagramming the letters (a peculiar or strange ordering of the letters).
'cit' written backwards gives 'tic'.
'places' is an anagram of 'scepal'.
'tic' placed within 'scepal' is 'SCEPTICAL'.
(Other definitions for sceptical that I've seen before include "dubious" , "Doubtful" , "Inclined not to believe" , "Inclined to disbelieve, not convinced" , "Disinclined to believe" .)