Is this piece a timepiece? (6)
I believe the answer is:
period
'is this piece' is the definition.
The answer and definition can be both related to communication as well as being singular nouns.
Perhaps you can see an association between them that I can't see?
'a timepiece?' is the wordplay.
I cannot quite see how this works, but
'a' could be 'per' (eg 'one a day' means 'one per day') and 'per' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for period that I've seen before include "Full stop or time interval" , "Era, epoch" , "term" , "Indefinite length of time" , "End of story" .)