Morning mist (3)
I believe the answer is:
dew
'morning mist' 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 "Condensation at beginning or end of day" , "Condensation during the night" , "Night fall of moisture" , "Early morning moisture" , "The damp of early morning" .)