Dynamic fellow overwhelmed by disastrous lure of cocaine (8)
I believe the answer is:
forceful
'dynamic' is the definition.
(similar in meaning)
'fellow overwhelmed by disastrous lure of cocaine' is the wordplay.
'fellow' becomes 'f' (abbreviation - of a society etc.).
'overwhelmed by' means one lot of letters goes inside another.
'disastrous' is an anagram indicator.
'cocaine' becomes 'c' (drugs abbreviation).
'lure'+'of'='lureof'
'lureof' is an anagram of 'oreful'.
'oreful' placed around 'c' is 'orceful'.
'f'+'orceful'='FORCEFUL'
(Other definitions for forceful that I've seen before include "Assertive, vigorous" , "Full of strength" , "Persuasive" , "Powerful and effective" , "Powerful, assertive" .)