Show hesitation in a way many may be rude about (5)
I believe the answer is:
demur
'show hesitation in a way' is the definition.
The answer and definition can be both related to communication as well as being singular nouns.
Maybe you can see a link between them that I can't see?
'many may be rude about' is the wordplay.
'many' becomes 'M' (Roman numeral for a thousand).
'may be' indicates anagramming the letters.
'about' indicates putting letters inside.
'rude' is an anagram of 'deur'.
'm' inserted inside 'deur' is 'DEMUR'.
Can you help me to learn more?
(Other definitions for demur that I've seen before include "Object gently" , "Protest mildly, show reluctance" , "Politely disagree" , "Protest or disagree mildly" , "Protest mildly, object" .)