מִשְׁמֶרֶתmishmerethStrong's H4931

watch, i.e. the act (custody), or (concretely) the sentry, the post; objectively preservation, or (concretely) safe; figuratively observance, i.e. (abstractly) duty or (objectively) a usage or party

Derivation: feminine of מִשְׁמָר (H4929)