Fail to credit spray-on corrosion (8)
I believe the answer is:
mistrust
'fail to credit' is the definition.
I can't judge whether this definition defines the answer.
'spray-on corrosion' is the wordplay.
'spray' becomes 'mist' (misting is a kind of spraying).
'on' is a charade indicator (letters next to each other).
'corrosion' becomes 'rust' (rust is a kind of corrosion).
'mist'+'rust'='MISTRUST'
Can you help me to learn more?
(Other definitions for mistrust that I've seen before include "reservations" , "Suspect (someone)" , "Lack of belief (in someone)" , "Have no confidence in (someone)" , "Regard with suspicion" .)