Film department returned to put holes in lawn (6)
I believe the answer is:
aerate
'put holes in lawn' is the definition.
(aerate can mean to circulate air through a lawn)
'film department returned' is the wordplay.
'film' becomes 'ET' (E.T. the Extra-Terrestrial).
'department' becomes 'area' (someone's department is their area of expertise).
'returned' shows that the letters should be reversed in order.
'et'+'area'='etarea'
'etarea' backwards is 'AERATE'.
'to' is the link.
(Other definitions for aerate that I've seen before include "Charge with carbon dioxide" , "Fill with bubbly gas" , "Pass bubbles through?" , "Send out, broadcast" , "Let in oxygen" .)