Could be happiest last words (8)
I believe the answer is:
epitaphs
'last words' is the definition.
The definition and answer can be both related to communication as well as being plural nouns.
Perhaps you can see a link between them that I can't see?
'could be happiest' is the wordplay.
'could be' indicates anagramming the letters.
'happiest' anagrammed gives 'EPITAPHS'.
Can you help me to learn more?
(Other definitions for epitaphs that I've seen before include "Gravestone inscriptions" , "words in grave situations" , "Happiest (anag)" , "Happiest sort of inscriptions on tombs" , "Famous last words" .)