Linen (4)
I believe the answer is:
lawn
'linen' is the definition.
(I have seen 'Fine linen' mean 'lawn' so perhaps 'linen' could also mean 'lawn')
This is the entire clue.
(Other definitions for lawn that I've seen before include "Fine cotton or grass garden" , "Expanse of grass" , "Fine cotton or smooth grass" , "Stretch of grass" , "type of tennis" .)