Plant holly without filling in, being lazy (4-3)
I believe the answer is:
work-shy
'lazy' is the definition.
('work-shy' can be a synonym of 'lazy')
'plant holly without filling in' is the wordplay.
'plant' becomes 'works' ('works' can be a synonym of 'plant').
'without filling in' means to remove the middle letters.
'holly' with its middle removed is 'hy'.
'works'+'hy'='WORK-SHY'
'being' acts as a link.
(Other definitions for work-shy that I've seen before include "Indisposed to labour" , "Lazy" .)