Old soldier in the glove trade (3)
I believe the answer is:
vet
'old soldier' is the definition.
(I've seen this in another clue)
'in the glove trade' is the wordplay.
'in' indicates a hidden word.
'VET' is hidden in the letters of 'the glove trade'.
(Other definitions for vet that I've seen before include "Animal doctor, in brief" , "'Examine this doctor, in short (3)'" , "Dog doc?" , "Examine, check" , "animal doctor to > investigate" .)