respectful title for high-ranking immortals in Taoism (e.g. 纯阳真君 chún​yáng​zhēn​jūn)

(literary) the absolute ruler or master of all things, often used in classical philosophical texts to describe the source of all being

short form of the Taiping Zhenjun (太平真君 tài​píng​zhēn​jūn) era name, a reign title of Emperor Taiwu of Northern Wei (440–451)