Tacky bloke reportedly on addictive drug (8)
I believe the answer is:
gimcrack
'tacky' is the definition.
(synonyms)
'bloke reportedly on addictive drug' is the wordplay.
I cannot quite see how this works, but
'drug' could be 'crack' (crack is a kind of drug) and 'crack' is located in the answer.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for gimcrack that I've seen before include "Of ornament, showy but worthless" , "poorly-made article" , "Rubbish!" , "Trashy" , "Tinpot" .)