The character, 體 (tai) which I think loosly means entity looks different than the what I have noticed in other characters. In particular, the radical on the left looks strange. I tried to find it on the internet, but I couldn't find anything about the etymology. Does anyone else know?
The character of 體 (today 体 in 当用漢字) meaning the body is composed of the characters of 骨 meaning human and creatures’ bones on the left side and 豊 meaning rich on the right side.
According to「常用字解」compiled by the great scholar, Chinese character / language etymologist, 白川静 and published by 平凡社, the letter of 骨 features the shape of the bones above the sternum with the fresh meat attached to as its origin (p.211). The letter of 豊 features 豆 shaping a jar with high legs full of millet, thus symbolizing abundance and fertility (p.585).
In ancient China, 體 meant the body of animal for an offer for sacrifice to the Heavenly God, and later came to mean human body (p.415).
In Japanese,「豊」is a merger of two unrelated but graphically similar characters:「豊」and「豐」. Only「豐」means abundance;「豊」was the original character for「禮」(Shinjitai:「礼」), meaning courtesy/etiquette.「豊」does not contribute meaning towards「體」.
「體」(Baxter-Sagart OC: /*r̥ˤijʔ/) is comprised of semantic「骨」and phonetic「豊」(Baxter-Sagart OC: /*[r]ˤijʔ/).
In Ancient Chinese,「體」meant limbs. Quote from Analects:
If the four limbs aren't diligent, the five grains won't be ready for harvest.
體 is the old traditional-Chinese spelling (旧字体【きゅうじたい】) of modern simplified spelling (新字体【しんじたい】) 体.
The radical of the older form is 骨, "bone".
More information about the character is available on Wiktionary: