アン, おそ.い

late, quiet, sets (sun)

JLPT1 G13 S0 F5000

As per # (rest in/on) + sun/day → *setting of the sun* (sun resting/settling on the horizon; compare ) → *late* (← late in the day); *quiet* (that accompanies the end of the day).

[Full Kanji Etymology List]