- residual (adj.)
[residual 词源字典]
- 1560s, from residue + -al (1), or from French résiduel, from Latin residuum.[residual etymology, residual origin, 英语词源]
- residual (n.)
- 1550s, in mathematics, from residual (adj.) or from residue + -al (2). Residuals "royalties" attested by 1960.