Asymptote
Pronunciation : As"ymp*tote
Part of Speech : n.
Etymology : [Gr. Symptom.] (Math.)
Definition : Defn: A line which approaches nearer to some curve than assignable distance, but, though infinitely extended, would never meet it. Asymptotes may be straight lines or curves. A rectilinear asymptote may be conceived as a tangent to the curve at an infinite distance.
Source : Webster's Unabridged Dictionary, 1913