noun, noun which may take the genitive case particle 'no'
another matter; separate case; different issue
Used to indicate that something is a different topic, case, or project from the one currently under discussion. Often used in business or formal contexts.
That's a separate matter and has nothing to do with what we're discussing now.
I have a meeting for another project, so I'll excuse myself first.
arrest on a separate charge
Compound of 別 (separate) and 件 (matter, case).