A kowtow is an act of deep respect shown by prostration, specifically kneeling and bowing low enough to touch one's head to the ground. In Sinospheric cultures, it is the highest form of reverence. Historically, it was used to show respect to elders, superiors, or ancestors, and in some cases, to show submission to a ruler or deity. The term is also used figuratively to describe excessive deference or submission to someone in a position of authority.