An Etymological Dictionary of Astronomy and Astrophysics

A straight line which is approached, but never reached, by an infinite branch of a curve, and which can be regarded as a line tangent to the curve at infinity.

Etymology (EN): Gk. asymptotos “not falling together,” from → a- “not” + → syn “with” + ptotos “fallen,” verbal adj. from piptein “to fall”.

Etymology (PE): Nâhamsâv, literally “not touching each other,”
from nâ- “not” + ham “with” (akin to Gk. syn-) + sâv, agent noun of sâvidan “to touch.”