Well-armed character that squirms when caught (7)
I believe the answer is:
octopus
'well-armed character' is the definition.
'squirms when caught' is the wordplay.
I cannot quite understand how this works, but
'caught' could be 'ct' and 'ct' is located in the answer.
This may be the basis of clue (or it may be nonsense).
'that' acts as a link.
Can you help me to learn more?
(Other definitions for octopus that I've seen before include "Eight-armed mollusc" , "something from La Mer?" , "From influential organisation" , "Influential person" , "Tentacled marine mollusc" .)