Vagrant brought in who boozes (4)
I believe the answer is:
hobo
'vagrant' is the definition.
(I know that hobo is a type of vagrant)
'brought in who boozes' is the wordplay.
'brought in' indicates the answer is hidden within the clue.
'HOBO' can be found hidden inside 'who boozes'.
(Other definitions for hobo that I've seen before include "Bum" , "Vagrant (US)" , "Vagrant, tramp" , "Itinerant" , "American tramp" .)