A guy relaxed (2,4)
I believe the answer is:
at ease
'relaxed' is the definition.
('at ease' can be similar in meaning to 'relaxed')
'a guy' is the wordplay.
'guy' becomes 'tease' (I've seen this before).
'a'+'tease'='AT EASE'
(Other definitions for at ease that I've seen before include "'Relaxed (2,4)'" , "Army command to relax, stand with feet apart" , "Relaxing - that's a military order" , "Relaxed, not tense - that's an order" , "In a relaxed attitude" .)