The word "老子" (Lǎozǐ) is formed through a classic Chinese nominal construction where the prefix "老" (lǎo), meaning "old" or "venerable", is attached to the philosophical suffix "子" (zǐ), meaning "master" or "philosopher", to create an honorific title meaning "the Old Master", primarily referring to the ancient Taoist sage and author of the Daodejing. In its other, colloquial usage meaning "I, your father" (used arrogantly in speech), the same characters undergo a semantic shift where "老" retains its sense of seniority but is used familiarly/affectionately, and "子" here functions as a diminutive suffix meaning "child", so the compound literally means "old child", but is used idiomatically as a self-assertive first-person pronoun rooted in patriarchal family structure.