It is dropped on the grass (3)
I believe the answer is:
dew
'it is dropped on the grass' is the definition.
The definition suggests a singular noun which matches the answer.
This is the entire clue.
(Other definitions for dew that I've seen before include "It forms on cool surfaces at night" , "Morning condensation as on grass" , "Moisture on ground" , "Small drops of moisture" , "Early morning moisture" .)