No quarter! (5)
I believe the answer is:
fifth
This might be a double definition.
'no' is the first definition.
The answer and definition can be both related to communication as well as being singular nouns.
Maybe there's a link between them I don't understand?
'quarter' is the second definition.
The answer and definition can be both quantities as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
Can you help me to learn more?
(Other definitions for fifth that I've seen before include "20 per cent" , "Interval of three tones and a semitone" , "Next after fourth" , "Fraction" , "Musical interval" .)