english
1
general::
Phrase(s): in passing casually; said or mentioned as an aside. • I just heard your name in passing. I didn’t hear more than that. • The lecturer referred to George Washington in passing.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Incidentally, by the way, as in "It may be remarked in passing" (Charlotte Brontë, Shirley, 1849). [Mid1800s]
American Heritage Idioms