Merriam-Webster's Collegiate® Dictionary, 11th Edition
KOWTOW
I. noun
Etymology: Chinese (Beijing) kòutóu, from kòu to knock + tóu head
Date: 1804
an act of kowtowing,
II. intransitive verb
Date: 1826
to show obsequious deference ; fawn , to kneel and touch the forehead to the ground in token of homage, worship, or deep respect