Chaperon about to arrive — retired woman (6)
I believe the answer is:
duenna
'chaperon' is the definition.
(I know that duenna is a type of chaperon)
'about to arrive retired woman' is the wordplay.
'about to arrive' becomes 'due' (I've seen this in another clue).
'retired' shows that the letters should be reversed in order.
'woman' becomes 'ann' (woman's name).
'ann' reversed gives 'nna'.
'due'+'nna'='DUENNA'
(Other definitions for duenna that I've seen before include "Governess, chaperone" , "Spanish chaperon or governess" , "governess in Spain" , "Woman chaperon in Hispanic countries" , "Chaperon to young girl in Spain" .)