Moisture finally dried with sprinkling of powder (7)
I believe the answer is:
dewdrop
'moisture' is the definition.
(dew is moisture)
'finally dried with sprinkling of powder' is the wordplay.
'finally' suggests the final letters.
'with' says to put letters next to each other.
'sprinkling of' indicates an anagram (the letters are sprinkled or scattered around).
The last letter of 'dried' is 'd'.
'powder' anagrammed gives 'ewdrop'.
'd'+'ewdrop'='DEWDROP'
(Other definitions for dewdrop that I've seen before include "A globule of morning moisture" , "Morning condensate" , "Bit of condensed water" , "Powder'd (anag.)" , "Precipitation" .)