to pour wine on the ground as a ritual offering to the gods or ancestors in ancient times

the person chosen to perform the libation ritual at a banquet, usually the most senior or respected person present; also used as an honorific for such a person

the most senior and respected person in a field or profession, such as literature or academia

a high-ranking official title in imperial China, notably the head of the Imperial College 国子监 guó​zǐ​jiàn from the Han dynasty until the late Qing