a promise / an appointment or social engagement (the meeting itself) / a convention; something that is conventional / something that is preordained

一躍:

一約: / 一躍: / 一龠: a unit of volume equal to 1,200 millet grains

一躍:

to promise; to make a promise / make an appointment or engagement / be predestined, wait

(archaic) to stand watch over something, to be on the lookout for something (such as a watchman controlling entry to a place) / (archaic) to protect or defend something, to ensure that something is safe

護る: to protect, to defend / to watch carefully / to abide (by rules), to observe (regulations)

(Classical Japanese) to be watching continuously, to be on watch repeatedly, to be on look out

(Classical Japanese) to be watching continuously, to be on watch repeatedly, to be on look out / (Classical Japanese) to protect something, to take care of something

(Classical Japanese) to be watching continuously, to be on watch repeatedly, to be on look out / (Classical Japanese) to protect something, to take care of something