Losing opener, curse sport (4)
I believe the answer is:
wear
'sport' is the definition.
(sport can mean to wear or display on one's person)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for wear that I've seen before include "Clothes; chafe" , "Become tiresome" , "Durham river" , "Northern runner" , "show" .)