Pothead captured in bust on Erraid (6)
I believe the answer is:
stoner
'pothead' is the definition.
(both can mean a drug user)
'captured in bust on erraid' is the wordplay.
'captured in' indicates a hidden word.
'STONER' can be found hidden inside 'bust on erraid'.
(Other definitions for stoner that I've seen before include "No rest (anag) - cannabis user" , "Slang for habitual pot-smoker" , "Slang for habitual smoker of cannabis" .)