Words recited in panto, perhaps, when horse enters (8)
I believe the answer is:
antiphon
'words' 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?
'recited in panto perhaps when horse enters' is the wordplay.
I cannot quite understand how this works, but
'when' could be 'on' (I've seen this in other clues) and 'on' is present in the answer.
'horse' could be 'h' (abbreviation as in horse power) and 'h' is present in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for antiphon that I've seen before include "Short sentence" , "Musical church response" , "Item sung in church" , "Type of church music" , "No hatpin, curiously, for the responsorial song" .)