Maiden on my arm, courtship foolish, all concluding (5)
I believe the answer is:
nymph
'maiden' is the definition.
(I've seen this before)
'on my arm courtship foolish all concluding' is the wordplay.
'all concluding' suggests the final letters.
The last letters of 'on my arm courtship foolish' are 'NYMPH'.
(Other definitions for nymph that I've seen before include "Minor goddess of nature" , "Mythological spirit of nature imagined as a beautiful maiden" , "Young dragonfly" , "Mythological spirit - larva" , "Gorgeous girl" .)