Expression in dance, sure quirky (9)
I believe the answer is:
discourse
'expression' is the definition.
The definition and answer can be both related to communication as well as being singular nouns.
Maybe you can see an association between them that I can't see?
'dance sure quirky' is the wordplay.
'dance' becomes 'disco' (I've seen this before).
'quirky' is an anagram indicator.
'sure' with letters rearranged gives 'urse'.
'disco'+'urse'='DISCOURSE'
'in' acts as a link.
Can you help me to learn more?
(Other definitions for discourse that I've seen before include "Communication verbally" , "(Formal) talk" , "Engage in conversation; debate" , "Conversation, dialogue" , "Formal discussion of a topic" .)