Arm section infiltrating all-powerful nation (4)
I believe the answer is:
ulna
'arm section' is the definition.
The definition and answer can be both body parts as well as being singular nouns.
Perhaps there's an association between them I don't understand?
'infiltrating all-powerful nation' is the wordplay.
'infiltrating' indicates a hidden word.
'ULNA' can be found hidden inside 'all powerful nation'.
Can you help me to learn more?
(Other definitions for ulna that I've seen before include "Part of bone-structure" , "Thinner of two long bones in forearm" , "part of anatomy" , "One in arms" , "The longer and inner bone in forearm" .)