noun
digression; aside; tangent
Used for a remark or story that goes off the main topic, often in conversation or writing. Common in phrases like 余談ですが (as an aside) or 余談はさておき (digressions aside).
余談ですが、彼は来月結婚するそうです。
As an aside, I hear he's getting married next month.
余談
Digressions aside, let's get to the main topic.