What you might get for breakfast in London, in a manner of speaking (7)
I believe the answer is:
english
'speaking' is the definition.
The answer and definition can be both related to communication as well as being singular nouns.
Perhaps you can see a link between them that I don't see?
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for english that I've seen before include "A country condiment?" , "spin?" , "Would he sling out the language?" , "An official language of the Republic of India" , "speech" .)