Charming in branch (3)
I believe the answer is:
arm
'branch' is the definition.
(synonyms)
'charming in' is the wordplay.
'in' says the answer is hidden in the clue.
'ARM' can be found hidden inside 'charming'.
(Other definitions for arm that I've seen before include "Activate fuse" , "Test of strength with elbows on the table" , "strip of land?" , "Steel" , "Equip with weapons" .)