Curious million following sport (3)
I believe the answer is:
rum
'curious' is the definition.
(synonyms)
'million following sport' is the wordplay.
'million' becomes 'm' (abbreviation).
'following' means one lot of letters go next to another.
'sport' becomes 'RU' (rugby union).
'm' after 'ru' is 'RUM'.
(Other definitions for rum that I've seen before include "Strange drink from molasses" , "Droll" , "Peculiar like sailor's drink (3)" , "An alcoholic spirit - sounds odd" , "Eerie" .)