Nothing green apparent (5)
I believe the answer is:
overt
'apparent' is the definition.
(thesaurus)
'nothing green' is the wordplay.
'nothing' becomes 'o' (looks like zero - 0).
'green' becomes 'vert' (I've seen this before**).
'o'+'vert'='OVERT'
(Other definitions for overt that I've seen before include "Open,up front" , "Open and candid" , "____ is able to be seen" , "Not locked away" , "not disguised" .)