by the bye
[adverb]
Synonyms: incidentally, by the way, in passing, obiter, parenthetically

[TahlilGaran] English Synonym Dictionary ▲

by the bye
{adv. phr.} Just as some added fact or news; as something else that I think of. - Used to introduce something related to the general subject, or brought to mind by it.
We shall expect you; by the way, dinner will be at eight.

I was reading when the earthquake occurred, and, by the way, it was The Last Days of Pompeii that I was reading.

See: BY THE WAY.

[TahlilGaran] English Idioms Dictionary ▲