Criminal noticing jacketless cop in a disguise (9)
I believe the answer is:
incognito
'a disguise' is the definition.
(thesaurus)
'criminal noticing jacketless cop' is the wordplay.
I cannot really see how this works, but
an anagram of 'noticing' is 'incognit' which is located in the answer.
A single letter 'o' 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).
'in' is the link.
Can you help me to learn more?
(Other definitions for incognito that I've seen before include "with unknown identity" , "Under assumed identity" , "as something else" , "On the sly" , "With identity kept secret, perhaps travelling thus" .)