守更

守更	shǒu gēng	to keep watch during the night
守	shǒu	to guard / to defend / to keep watch / to abide by the law / to observe (rules or ritual) / nearby / adjoining
更	gēng	to change or replace / to experience / one of the five two-hour periods into which the night was formerly divided / watch (e.g. of a sentry or guard)
更	gèng	more / even more / further / still / still more