Incidentally
来自Big Physics
early 17th century: originally from medieval Latin incidentalis, from Latin incident- ‘falling upon, happening to’ (from the verb incidere ).
wiktionary
incidental + -ly
etymonline
incidentally (adv.)
1520s, "by the way, casually;" see incidental + -ly (2). Sense of "as a new but related point" attested by 1925.
