Kowtow
Kowtow , 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; same as Kotow. There are degrees in the rite, the highest being expressed by three knockings. [China] — S. W. Williams
Kowtow , intransitive verb
To perform the kowtow. Same as Kotow
I have salaamed and kowtowed to him.
2.
To defer to another in a servile or humiliating manner; to act obsequiously.