Uncertain expressions about animal's howler? (7)
I believe the answer is:
erratum
'howler?' is the definition.
The definition and answer can be both related to communication as well as being singular nouns.
Maybe you can see an association between them that I can't see?
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for erratum that I've seen before include "Misprint" , "Printing mistake" , "mistake in text" , "A mistake in printed matter" , "Faux pas" .)