From lips come arts of disputation (8)
I believe the answer is:
polemics
'arts of disputation' is the definition.
The answer and definition can be both related to communication as well as being plural nouns.
Perhaps they are linked in a way I don't understand?
'from lips come' is the wordplay.
'from' indicates anagramming the letters (the anagram comes from the same letters).
'lips'+'come'='lipscome'
'lipscome' with letters rearranged gives 'POLEMICS'.
Can you help me to learn more?
(Other definitions for polemics that I've seen before include "Complies with verbal attacks on opinions" , "arguments" , "Compiles into verbal attacks on beliefs" .)