Maybe trawl centre of Croydon for suspect (5)
I believe the answer is:
fishy
'for suspect' is the definition.
(synonyms)
'maybe trawl centre of croydon' is the wordplay.
I cannot quite understand how this works, but
'trawl' could be 'fish' (I've seen this before) and 'fish' is present in the answer.
A single letter 'y' remains which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for fishy that I've seen before include "Suspect" , "Questionable" , "Arousing suspicion" , "Ray is so" , "Suspicious in piscine way" .)