Gather together after action - demob happy at last (6)
I believe the answer is:
embody
'gather together after' is the definition.
I can't judge whether this defines the answer.
'action demob happy at last' is the wordplay.
'action' indicates anagramming the letters.
'at last' indicates one should take the final letters.
The last letter of 'happy' is 'y'.
'demob' with letters rearranged gives 'embod'.
'embod'+'y'='EMBODY'
Can you help me to learn more?
(Other definitions for embody that I've seen before include "Contain within oneself, incorporate" , "concretise" , "Give a visible form to" , "Give solid form to" , "Give form to (idea)" .)