Guide bad deal (4)
I believe the answer is:
lead
'guide' is the definition.
(lead can mean to usher or guide)
'bad deal' is the wordplay.
'bad' indicates anagramming the letters.
'deal' is an anagram of 'LEAD'.
(Other definitions for lead that I've seen before include "conductor of electricity" , "initiative" , "Metal; clue" , "Chief performer" , "Metal - van - important role" .)