Rest, with no top, in the grass (7)
I believe the answer is:
holiday
'rest' is the definition.
(thesaurus)
'no top in the grass' is the wordplay.
'no' becomes 'o' (resembles 0 - 'no' can mean 'zero').
'top' becomes 'lid' (lid is a kind of top).
'in the' indicates putting letters inside.
'grass' becomes 'hay' (I have seen 'Mown grass ' mean 'hay' so perhaps 'grass' could also mean 'hay').
'o'+'lid'='olid'
'olid' going within 'hay' is 'HOLIDAY'.
'with' is the link.
(Other definitions for holiday that I've seen before include "Time off work" , "Day of festivity" , "given a break" , "Billie" , "Vacation" .)