Questionable (4)
'questionable' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for iffy that I've seen before include "Questionable - uncertain" , "Colloquially uncertain or doubtful" , "Informally dubious or uncertain" , "Questionable (inf)" , "Not to be trusted" .)
'questionable' is the definition.
(similar in meaning)
This is all the clue.
(Other definitions for suspect that I've seen before include "Dubious" , "Dodgy" , "Possible criminal - doubtful" , "Believe without being certain" , "one on bail, perhaps" .)
'questionable' is the definition.
(similar in meaning)
This is all the clue.
(Other definitions for dubious that I've seen before include "Uncertain - suspect" , "Arousing suspicion" , "Unsure, unconvinced" , "unreliable" , "Doubtful, uncertain" .)
'questionable' is the definition.
(similar in meaning)
This is the entire clue.
(Other definitions for problematic that I've seen before include "Potentially difficult" , "Difficult; doubtful" , "Troublesome" , "tricky" , "Presenting difficulties" .)