Threadbare throw worn by abbess (6)
I believe the answer is:
shabby
'threadbare' is the definition.
(I've seen this before)
'throw worn by abbess' is the wordplay.
'throw' becomes 'shy' (shy can mean to throw or sling).
'worn by' indicates putting letters inside (outside letters are worn by those on the inside).
'abbess' becomes 'abb'.
'shy' placed around 'abb' is 'SHABBY'.
(Other definitions for shabby that I've seen before include "Old and worn - mean" , "Scruffy; unfair" , "Of clothes, worn and threadbare (6)" , "Seedy and rundown" , "Moth-eaten - dishonourable" .)