Tailored thing you and I regularly assume at first when retiring (9)
I believe the answer is:
nightwear
'tailored thing you and i regularly assume at first when retiring' is the definition.
I can't tell whether this defines the answer.
'tailored thing you and i regularly assume at first when retiring' is the wordplay.
'tailored' indicates anagramming the letters (the letters are customised ).
'you and i' becomes 'we' (we means you and I).
'at first' suggests taking the first letters.
'when retiring' is a reversal indicator (retire can mean to go back).
The first letters of 'regularly assume' is 'ra'.
'ra' reversed gives 'ar'.
'thing' is an anagram of 'night'.
'night'+'we'+'ar'='NIGHTWEAR'
Can you help me to learn more?
(Other definitions for nightwear that I've seen before include "negligee, say" , "What's put on kippers" , "this brings bed to mind?" , "negligee, perhaps" , "Pyjamas, for example" .)