noun
point at infinity
Mathematical term used in projective geometry and related fields to represent an ideal point where parallel lines meet.
射影幾何学では、平行線は無限遠点で交わる。
In projective geometry, parallel lines intersect at a point at infinity.
Compound of 無限 (infinite) + 遠 (distant) + 点 (point). A calque from Western mathematical terminology.