Dad's taken aback by servant admitting close attachment (9)
I believe the answer is:
appendage
'attachment' is the definition.
(thesaurus)
'dad's taken aback by servant admitting close' is the wordplay.
'dad' becomes 'pa' (both can mean one's father).
'taken aback' shows that the letters should be reversed in order.
'by servant' becomes 'page' (a royal servant. I am not sure about the 'by' bit.).
'admitting' means one lot of letters goes inside another (admit can mean to welcome in or accept).
'close' becomes 'end' (close can mean to end or finish).
'pa' backwards is 'ap'.
'page' going around 'end' is 'pendage'.
'ap'+'pendage'='APPENDAGE'
Can you help me to learn more?
(Other definitions for appendage that I've seen before include "Attached item" , "An outgrowth" , "Thing attached to another" , "It's added or attached to a larger or more important part" , "Addendum" .)