Literary posers will produce vexed expressions (10)
I believe the answer is:
crosswords
'literary posers' is the definition.
The answer and definition can be both related to communication as well as being plural nouns.
Maybe they are linked in a way I don't understand?
'vexed expressions' is the wordplay.
'vexed' becomes 'cross' (both can mean angry).
'expressions' becomes 'words' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'cross'+'words'='CROSSWORDS'
'will produce' is the link.
Can you help me to learn more?
(Another definition for crosswords that I've seen is " which call for solutions".)