(after a verb or adjective) one who (is) ... / (after a noun) person involved in ... / -er / -ist / (used after a number or 後|后[hou4] or 前[qian2] to refer to sth mentioned previously) / (used after a term, to mark a pause before defining the term) / (old) (used at the end of a command) / (old) this
to guard / to protect / to defend / abbr. for 衛生|卫生, hygiene / health / abbr. for 衛生間|卫生间, toilet / surname Wei / vassal state during the Zhou Dynasty (1066-221 BC), located in present day Henan and Hebei Provinces