Scornful criticisms from a sister (7)
I believe the answer is:
'scornful criticisms' is the definition.
The definition and answer can be both related to communication as well as being plural nouns.
Maybe you can see a link between them that I can't see?
'from a sister' is the wordplay.
'from' indicates an anagram (the anagram comes from the same letters).
'asister' anagrammed gives 'SATIRES'.
Can you help me to learn more?
(Other definitions for satires that I've seen before include "travesties?" , "A sister (anag.)" .)