Often seen displaying form of verb (5)
I believe the answer is:
tense
'form of verb' is the definition.
The answer and definition can be both related to communication as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'often seen displaying' is the wordplay.
'displaying' indicates the answer is hidden within the clue.
'TENSE' can be found hidden inside 'often seen'.
Can you help me to learn more?
(Other definitions for tense that I've seen before include "imperfect, perhaps?" , "In a nervous state" , "Uneasy" , "Attribute of verbs signalling time" , "Present, possibly" .)