Place to leave complaint, and make another (4)
I believe the answer is:
ague
'place' is the definition.
The definition and answer can be both related to communication as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for ague that I've seen before include "met with cheek in Twelfth Night" , "Sickness" , "Acute fever; shivering fit" , "nasty illness?" , "Feverish fit" .)