Turn one's back on Shaw getting out of sash window (6)
I believe the answer is:
disown
'out of sash window' is the definition.
Although both the answer and definition are verbs in their base form, I can't see how they can define each other.
'turn one's back on shaw' is the wordplay.
I cannot really see how this works, but
'one's' could be 'is' (Roman numeral) and 'is' is found in the answer.
'turn' could be 'down' (down is a kind of turn) and 'down' is present in the leftover letters.
No letters remain.
This explanation may well be incorrect...
'getting' is the link.
Can you help me to learn more?
(Other definitions for disown that I've seen before include "Reject all connection or relationship with" , "Deny any connection with" , "Refuse responsibility for" , "Forsake" , "Repudiate or refuse to acknowledge a relationship" .)