During my visit to Beijing in November 2012, I found a huge bookstore. It was more like a department store (six stories high) for books. It had an extensive section on Wushu and there were many tai chi titles of all styles.
I came across a book called Li Jing-Wu's Tai Chi Neigong and his Cherished Manual 李經梧 太極內功及所藏秘譜 written by his disciple. Li Jing-Wu was the Wu style tai chi master.
In this book, there is a section on the cherished manual (a reproduction of the handwritten copy of Li's manual). Also the author wrote some comments on his understanding of the manual.
This manual 太極拳秘宗* was given to Li by his sifu Zhao Tie-An 赵铁庵. Zhao copied from his own sifu's manual. All copying was done by hand. Each copier could substitute a character similar in sound in error. In fact, the author pointed out a few "typo" characters as he was comparing this manual with other similar manuals*.
This one (which might cause our generation of tai chi practitioners a wrong connotation on the intent of the move) concerned me.
The move is what we translated as "Repulse Monkey" or "Ward off Monkey" in present day parlance.
The Chinese characters in the old manual were 倒輦猴頭
倒輦 means repulse or ward off
猴頭 means monkey's head.
But 猴 was a mistake and it should be 喉. They sound exactly the same. The left side of the character indicated what group the character 猴 belongs to " 犭- animal" group and 喉 belongs to " 口 - mouth" group.
喉 means the throat.
喉頭 means head of the throat i.e. the Adam's apple
倒輦喉頭 means repulse the opponent at the throat; or strike his Adam's Apple with the hand.
Later on people shortened it to 倒輦猴
That is why it is translated as "Repulse Monkey"
In my opinion, Repulse Monkey gives me a wrong connotation of the move.
For combat use, striking the opponent's throat or grabbing the opponent's Adam's apple makes more sense.
When we do the tai chi as an exercise, it doesn't matter which intention one has, as long as we do it with good structure and motion.
But when we get to a higher level of tai chi and use intent to guide the movement, a proper intention is needed.
*a similar manual has appeared in books like 吳家太極拳 Wu Taiji Quan. This book has a section with a reproduction of a handwritten secret manual 手抄秘本 passed down from 吳全佑 Wu Quan-You to his son 吳鑑泉 Wu Chien-Chuan creator of Wu Style Tai Chi.
Also in 楊澄甫式太極拳 Yang Chen-Fu's Taijiquan by 楊振基 Yang Zhen-Ji contains a section of reproductions of a 太極拳老拳譜 Taijiquan "old style" instruction manual.
They all stated the same thing except using different characters for some words.
It looks like those manuals were copied from the same unconfirmed source.