Longman Dictionary of Contemporary English - passing

~1 n 1 the passing of time/the years the process of time going by  (With the passing of years, he grew more bad-tempered.) 2 mention/note in passing if you say something in passing, you mention it while you are mainly talking about something else  (He did mention his brother's wife, but only in passing.) 3 the fact of something ending or disappearing  (The old regime was defeated, and few people mourned its passing.) 4 a word meaning death, used when you want to avoid saying this directly ~2 adj only before noun 1 going past  (Michael watched the passing cars.) 2 with each passing day/week/year literary continuously as time passes  (With each passing day she grew stronger.) 3 short, or disappearing after only a short time; brief1 (1)  (He didn't even give the matter a passing thought. | a passing reference) ~3 adv old use very  (passing strange)