infinity

1. Endlessness, unlimitedness, absence of a beginning, end or limits to size.

2. A number that has an infinite numerical value that cannot be counted.

3. An idealised point which is said to be approached by sequences of values whose magnitudes increase without bound.

4. A number which is very large compared to some characteristic number. For example, in optics, an object which is much further away than the focal length of a lens is said to be "at infinity", as the distance of the image from the lens varies very little as the distance increases further.

5. The symbol ∞.