Drops on morning grass (3)
I believe the answer is:
dew
'drops on morning grass' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for dew that I've seen before include "Early morning condensation" , "Condensation during the night" , "Condensation at beginning or end of day" , "Night-time condensation" , "Morning or evening condensation" .)