Yes, of course India has a deep history of meditation and yoga and etymology does show relationship, but it is incorrect to say that it means the same thing in that place, most especially because the Sanskrit word itself wasn't purely preserved, it was mutated into a native sounding Chinese and Japanese word that took on a new, specific connotation reflecting the practice that evolved there in China.

A simple example of this is the meaning of "pudding" in British English vs American English.

> Pudding originally referred exclusively to varieties of sweet natural-casing sausage. The meaning grew to encompass anything boiled or steamed in a bag, then shifted to refer primarily to desserts, especially those cooked by boiling or steaming. Most recently, in American English, it has changed to refer exclusively to the thick custardy dessertstuff [1]

So this simple example illustrates that location can have a specific effect on the meaning and connotation of a word, and that a word may have a broad meaning from where it originates, but can have a very specific and different meaning elsewhere.

[1] https://english.stackexchange.com/a/12564

I do know how semantic change works, yes. And your pudding example shows that borrowing (and phonological adaptation) is likely beside the point. Words can change their meaning (and generally do) even when speakers are staying in the same geographic location (e.g. Sanskrit lokaḥ "world" became the Hindi plural marker log).

But all of this seems somewhat irrelevant to me for the topic at hand. Buddhism has a long history in India before reaching China, including meditative/concentration. Obviously there were significant developments in China (and Japan) which make Zen Buddhism distinct, but it seems odd to ignore the Indian Buddhist base it's built upon.

I'm not ignoring its foundation in India, only affirming that what we know of as Zen was critically developed in China and Japan. American English has roots in Britain, but it's distinctly American.