asymptote (n.)youdaoicibaDictYouDict[asymptote 词源字典]
"straight line continually approaching but never meeting a curve," 1650s, from Greek asymptotos "not falling together," from a- "not" + syn "with" + ptotos "fallen," verbal adjective from piptein "to fall" (see symptom). Related: Asymptotic.[asymptote etymology, asymptote origin, 英语词源]