1) Act of submission 2) Bowing 3) Kowtow 4) Obeisance 1) Bootlick 2) Kowtow 
• (n.) The prostration made by mandarins and others to their superiors, either as homage or worship, by knocking the forehead on the ground. There are degrees in the rite, the highest being expressed by three knockings. • (v. i.) To perform the kotow.
Ko·tow' intransitive verb [ imperfect & past participle Kotowed ; present participle & verbal noun Kotowing .] To perform the kotow. Ko·tow' noun [ Chinese, knock head.] The prostration made by mandarins and others to their superiors, either as homage or worship, by knocking the forehead on the ground. There are degrees in the rite, the highest being expressed by three knockings. [ China] S. W. Williams.