incidentally
adv. sent. B2 Upper Intermediate US //ˌɪnsɪˈdɛntəɫi// UK //ˌɪnsɪdˈɛntəli// in·ci·den·tal·ly
adv. used to add a piece of information that is not the main topic. You use it when you suddenly remember something extra to say.
adv. used to introduce a remark that is not directly related to the main subject of conversation. Often functions as a transition to a secondary or parenthetical point.
Incidentally, have you seen my keys anywhere?
We should finish the report by Friday; incidentally, the manager wants to see the first draft tomorrow.
The report highlights several structural flaws in the bridge; incidentally, these same issues were raised by the original engineering team nearly a decade ago but were never addressed.
From incidental + -ly.
Usage
Typically placed at the beginning of a sentence or clause to signal a shift in topic.