俯首
fǔ shoǔ · HSK 7
to bend one's head
🙇 俯 (bend down) + 首 (head) = bend one's head
俯 means to bow or lean forward; 首 is the classical word for head (still seen in 首都 capital, 首领 chief). Together: lower the head — often used for submission or deference.
首 — hair 丷 over face 自 (eye + nose)
首 is a pictograph of a head, originally drawn with hair on top and a face below (containing the eye element 目). It meant 'head' literally, then extended to 'chief, leader, first' since the head is the topmost and foremost part of the body.