It discharges a spray or emits a fluid (8)
I believe the answer is:
atomiser
'it discharges a spray' is the definition.
The definition suggests a singular noun which matches the answer.
'or emits a fluid' is the wordplay.
'fluid' indicates an anagram.
'or'+'emits'+'a'='oremitsa'
'oremitsa' is an anagram of 'ATOMISER'.
Can you help me to learn more?
(Other definitions for atomiser that I've seen before include "Device for reducing liquid to a fine spray" , "Spraying device - same riot (anag)" , "Dispenser for turning liquid into a fine spray" , "Fine spray producer" , "Container that releases liquid in a fine spray" .)