A group holding one rope. Someone shouts, and on that shout everybody pulls at the same moment, so the whole strength lands in one push. The word is the beat that makes the effort arrive together — and one push like that is enough to send something out of the way.
Inherited from Middle English have howe: heave means to pull or lift with effort, and ho is simply a shouted sound.
從中古英語 have howe 傳下來。heave 是使勁拉、使勁抬，ho 只是喊出來的聲音，兩個合起來就是一起用力時喊的那一句。
Wiktionary etymology_text supplied in packet (kaikki:3f6f69a190036ae4:1342461511)
One branch
一起用力的那一聲
這一族就是核心畫面本身：喊出來的那一拍，以及那一拍造成的那一推。
interjection · C1
A shout used to get a group of people to pull at the same moment, especially sailors pulling on a rope. It is an old-fashioned word, so you meet it most often in stories, songs and jokes.
嘿唷（一起用力的吆喝）