Oh, her ~n she sounds all right (3)
I believe the answer is:
kay
'right' is the definition.
Both the answer and definition are singular nouns.
Maybe there's a link between them I don't understand?
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for kay that I've seen before include "K" , "Eleventh letter; girl's name" .)