She's game! (7)
I believe the answer is:
lioness
'she's' is the definition.
Both the answer and definition are singular nouns.
Perhaps there's a link between them I don't understand?
'game' is the wordplay.
I cannot really understand how this works, but
'game' could be 'on' (both can mean willing) and 'on' is located in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for lioness that I've seen before include "Female pride member" , "She may have pride" , "predatory female'" , "One with pride" , "Female big cat" .)