I don't know that much about kanjis to be able to comprehend it fully when the character is broken down to elements, but I have seen that kind of explanation, although not yet for shikantaza itself. As for the "taza", yes, it was a Buddhist dictionary that came up with a meaning on its own, but in Chinese they still have it within everyday language, if a non-specialised dictionary is any indication.
Thank you Astus, you have inspired me to search and read Chinese, and I did not do it for ages... so I looked at the Chinese sites...
Yeah, I checked up with regular Chinese dictionary and it has its contemporary usage in modern language. I wonder how did it change in comparison to the original meaning, since many old Chinese terms do not carry anymore their original meaning. Anyway in the particular environment of dharma language the meaning can be different from everyday spoken language.
so I looked up at some zen Chinese sites... it is interesting how they approach term ST... Though they lost ST practice in China and it survived only in Japan. XX century ST within Chinese buddhism is an import from Japan, plus they could search any surviving texts they could find. Since beginning of the Ming dynasty there was no ST in China... I heard once only about one master, but it was 15 or 20 years ago when one teacher told me, so actually I do not remember now the name of this Ming master...
well I looked at the Chinese Buddhist dictionary 《現代禪教團根本教典》, under shikan taza... http://www.masterlee.url.tw/good/zentoo ... ok-047.htm
It is really funny, since among 54 quotations about ST, they started form analysis or rather interpretation of the 4 characters
so Chinese might be doing same what Japanese teachers.
But this part drew my attention:
And here 打坐 is used much in a zen sense, i.e. its more original meaning, not just as common endeavor. Anyway all 54 are more or less interesting. Unfortunately they do not quote exact sources.