incidentally
Definitions
In an incidental manner; as a minor accompaniment.
Used to introduce a topic not directly relevant to the main subject; by the way.
Examples
Incidentally, I ran into an old friend at the grocery store this morning.
The meeting was scheduled for noon, which, incidentally, is when I have my lunch break.
Synonyms
by the way accidentally fortuitously casually in passing tangentially coincidentally
Antonyms
intentionally deliberately purposely directly specifically pertinently relevantly