Odd cola drunk outside foreign casino (10)
I believe the answer is:
occasional
'odd' is the definition.
(thesaurus)
'cola drunk outside foreign casino' is the wordplay.
'drunk' is an anagram indicator.
'outside' indicates putting letters inside.
'foreign' indicates anagramming the letters (foreign order of the letters).
'cola' anagrammed gives 'ocal'.
'casino' with letters rearranged gives 'casion'.
'ocal' enclosing 'casion' is 'OCCASIONAL'.
(Other definitions for occasional that I've seen before include "Rare" , "table may be of such a type" , "table of a sort" , "Periodical" , "Periodic" .)