One banished from historic mansion leaving quietly? (5)
I believe the answer is:
exile
'one banished' is the definition.
(someone sent away)
'historic mansion leaving quietly?' is the wordplay.
'historic' becomes 'ex' (the prefix 'ex-' can mean former).
'mansion' becomes 'pile' (I've seen this in other clues).
'leaving' is a deletion indicator.
'quietly?' becomes 'p' (p for piano and quiet).
'pile' with 'p' removed is 'ile'.
'ex'+'ile'='EXILE'
'from' acts as a link.
(Other definitions for exile that I've seen before include "being always away from home" , "Enforced absence" , "eg Napoleon on Elba" , "Bar (someone) from their native country" , "One lives away from the home country" .)