Why do we call right “right” and left “left”?

It is often said that many words are arbitrary, i.e., spelling and pronunciation have no direct relation to the meanings of words. Some English words have their roots in Latin and other European languages, and often they are made up of “morphemes”. In such cases, it is possible to easily explain the etymology of the words. For example, when explaining the origins of the word “submarine”, you can easily explain that “sub” means “under” and “marine” means “sea”.
While it is possible to explain the etymology of some words, the etymology of other words is often not possible. The topic here is the etymology of “right” and “left”, i.e., why we call right “right” and left “left”. If you do some research, you will notice that no one has ever explained this.

In every language, sense of direction is extremely important. Perhaps they are important when referring to directions going somewhere and also when referring to parts of human bodies, as they are not bilaterally symmetrical. Among all the parts of the human body, the hands are apparently not bilaterally symmetrical, not in the sense of shape but in the sense of use because of handedness/one’s dominant arm.

Suppose you are in an ancient era when there were no such words as “right” or “left”, or simply suppose you are in a certain situation today in which you are playing a game and you must not use the words “right” and “left”. If you want to instruct someone to use his “right” hand without using the word “right”, how would you say this? It would perhaps make sense to say, “Use your suitable hand” unless the person is left-handed. Yes, “right” has a meaning of “suitable” as used in “finding the right person.” Therefore, it is speculated that the word “right” was first used as in the words “right hand”, which refers to the “suitable hand” or “proper hand”. Because the majority of us are right-handed, “right hand” in the sense of “suitable hand” or “proper hand” became synonymous with one’s right hand. That is how the word “right” was coined, although this perhaps happened in the days of Old English or the Proto-Germanic language, the ancestor language of English.