叩首 is read as こうしゅ (koushu) and means kowtow.
こうしゅ
koushu
たたく
to beat down the price
はたき
(feather) duster
たたき
finely chopped fish or meat (sometimes seared first)
ちくび
nipple
くび
head
げんしゅ
sovereign
てくび
wrist
あしくび
ankle
じしゅ
surrender (to the authorities)
とうしゅ
party leader
ぶしゅ
radical (of a kanji character)
いっしゅ
one tanka