point at infinity

noun3

1. •
   An asymptotic point in 3-dimensional space, viewed from some point, at which parallel lines appear to meet and which in perspective drawing is represented as a vanishing point.
2. •
   Any point added to a space to achieve projective completion.

   • As the degree form Y² or X² of a parabola has only a single root, it has only one point at infinity. — 1990
3. •
   An ideal point.

   • To describe a parabolic transformation f of the hyperbolic plane, we consider two parallel lines l and l’ and we call ω their common point at infinity. — 2012