Unemployed, fish round lake (4)
I believe the answer is:
idle
'unemployed' is the definition.
(similar in meaning)
'fish round lake' is the wordplay.
'fish' becomes 'ide' (type of fish).
'round' is an insertion indicator.
'lake' becomes 'L' (geographical abbreviation).
'ide' enclosing 'l' is 'IDLE'.
(Other definitions for idle that I've seen before include "Inert; lazy" , "Fruitless" , "Disliking work" , "Lied about being lazy or not working" , "Unoccupied or not in use" .)