Uncomfortable, a guy after trouble (3,2,4)
I believe the answer is:
ill at ease
'uncomfortable' is the definition.
('ill at ease' can be a synonym of 'uncomfortable')
'a guy after trouble' is the wordplay.
'a guy' becomes 'tease' (I've seen this before).
'after' means one lot of letters go next to another.
'trouble' becomes 'illa' (I can't justify this - if you can you should believe this answer much more).
'tease' after 'illa' is 'ILL AT EASE'.
Can you help me to learn more?
(Other definitions for ill at ease that I've seen before include "discomfited" , "Fidgety" , "Unsettled, anxious" , "Unsure and constrained in manner" , "wound up" .)