Pest is banished in shade (6)
I believe the answer is:
nuance
'shade' is the definition.
(I know that shade can be written as nuance)
'pest is banished' is the wordplay.
'pest' becomes 'nuisance' (both can mean an annoying person).
'banished' is a deletion indicator.
'nuisance' with 'is' taken out is 'NUANCE'.
'in' is the link.
(Other definitions for nuance that I've seen before include "Delicate shade of difference" , "Subtle difference of meaning" , "Subtle distinction or variation" , "A slight shade as of meaning" , "Subtle shade of meaning" .)