A moister ground arises from spray (8)
I believe the answer is:
atomiser
'spray' is the definition.
('atomiser' can be a synonym of 'spray')
'a moister ground' is the wordplay.
'ground' is an anagram indicator (grind the letters ).
'moister' is an anagram of 'tomiser'.
'a'+'tomiser'='ATOMISER'
'arises from' is the link.
(Other definitions for atomiser that I've seen before include "Dispenser spraying perfume as a fine mist" , "Fine spray producer" , "Amortise for spray-creating device" , "Device for making liquid into a fine spray" , "Dispenser for turning liquid into a fine spray" .)