Youngster worried to change form (6)
I believe the answer is:
pupate
'change form' is the definition.
Although both the answer and definition are verbs in their base form, I cannot understand how they can define each other.
'youngster worried' is the wordplay.
'youngster' becomes 'pup' (I've seen this in other clues).
'worried' becomes 'ate' (something worrying may eat someone up).
'pup'+'ate'='PUPATE'
'to' is the link.
Can you help me to learn more?
(Other definitions for pupate that I've seen before include "Change into a chrysalis" , "To develop biologically" , "Turn into a chrysalis" , "Become a chrysalis" , "What insects do" .)