壽終正寢

to die of old age / to die in one's bed at a ripe old age / (fig.) (of a structure or machine etc) to come to the end of its life

long life / old age / age / life / birthday / funerary / a surname

to die of old age / to live to a ripe old age / (fig.) (of sth) to come to an end (after a long period of service)

end / finish

first month of the lunar year

straight / upright / proper / main / principal / to correct / to rectify / exactly / just (at that time) / right (in that place) / (math.) positive

to lie down