radius的词源
英文词源
- radius (n.)
- 1590s, "cross-shaft," from Latin radius "staff, stake, rod; spoke of a wheel; ray of light, beam of light; radius of a circle," of unknown origin. Perhaps related to radix "root," but Tucker suggests connection to Sanskrit vardhate "rises, makes grow," via root *neredh- "rise, out, extend forth;" or else Greek ardis "sharp point."
The geometric sense first recorded 1610s. Plural is radii. Meaning "circular area of defined distance around some place" is attested from 1953. Meaning "shorter bone of the forearm" is from 1610s in English (the Latin word had been used thus by the Romans).
中文词源
词根词缀： -radi-射线,放射 + -us名词词尾
该词的英语词源请访问找单词词源英文版：radius 词源，radius 含义。
rad-,半径，根，-us,阳性格。
rad-,半径，根，-us,阳性格。
