Still not at home in level (4,3)
I believe the answer is:
even out
'level' is the definition.
(I know that level can be written as even out)
'still not at home' is the wordplay.
'still' becomes 'even' (synonyms).
'not at home' becomes 'out' (out can mean away from home).
'even'+'out'='EVEN OUT'
'in' is the link.
(Other definitions for even out that I've seen before include "reach consistent level" , "Make flat" , "Smooth" , "Make less varied" , "iron?" .)