What a bird may do when about to be put in prison? (5)
I believe the answer is:
preen
'what a bird may do' is the definition.
The definition suggests a singular noun but the answer is not.
'about to be put in prison?' is the wordplay.
'about' becomes 're' ('re' means regarding or about).
'to be put in' indicates putting letters inside.
'prison?' becomes 'pen' (both can mean an enclosure).
're' put into 'pen' is 'PREEN'.
'when' is the link.
Can you help me to learn more?
(Other definitions for preen that I've seen before include "Groom with great care" , "Maintain" , "Beautify" , "Dress with elaborate care" , "demonstrate pride" .)