Cubs cycling through Oregon drug complex (7)
I believe the answer is:
obscure
'complex' is the definition.
(thesaurus)
'cubs cycling through oregon drug' is the wordplay.
'cycling' is an anagram indicator.
'through' indicates putting letters inside (inserted letters go through the word).
'oregon' becomes 'or'.
'drug' becomes 'e' (E is another name for ecstasy).
'cubs' with letters rearranged gives 'bscu'.
'bscu' placed into 'or' is 'obscur'.
'obscur'+'e'='OBSCURE'
(Other definitions for obscure that I've seen before include "Like Jude, not well known" , "Conceal; uncertain" , "Jude may be" , "Unknown or unclear" , "Dim, indistinct or not well known" .)