Fourth dimension,

Definition of Fourth dimension:

1. A postulated spatial dimension additional to those determining length, area, and volume.

2. Time. This fourth dimension is required for locating an event in addition to the three dimensions (length, breadth, height) required for locating a point in space.

3. Time regarded as analogous to linear dimensions.

How to use Fourth dimension in a sentence?

1. Their momentum along the fourth dimension would appear as additional mass in three dimensions, so we would observe heavy photons or heavy electrons, for example.
2. As things change over time, a fourth dimension needs to be added to politics - and my way of doing this is to argue that what is the right course of action changes with time.