unlimited extent of time, space, or quantity; eternity; boundlessness; immensity.-unlimited capacity, energy, excellence, or knowledge; as, the infinity of god and his perfections.-endless or indefinite number; great multitude; as an infinity of beauties.-a quantity greater than any assignable quantity of the same kind.-that part of a line, or of a plane, or of space, which is infinitely distant. in modern geometry, parallel lines or planes are sometimes treated as lines or planes meeting at infinity.