One donned as a regular thing? (5)
I believe the answer is:
habit
'one donned' is the definition.
I can't judge whether this defines the answer.
'a regular thing?' is the wordplay.
'a regular' becomes 'hab' (I can't explain this - if you can you should believe this answer much more).
'thing?' becomes 'it'.
'hab'+'it'='HABIT'
'as' is the link.
Can you help me to learn more?
(Other definitions for habit that I've seen before include "Settled tendency" , "Custom or monk's robe" , "Routine - clothing" , "Regular practice" , "Propensity" .)