fourth dimension

American  

noun

1. Physics, Mathematics. a dimension in addition to length, width, and depth, used so as to be able to employ geometrical language in discussing phenomena that depend on four variables.

   Time is considered a fourth dimension for locating points in space-time.

2. something beyond the kind of normal human experience that can be explained scientifically.

   The story deals with ESP and other excursions into the fourth dimension.

---

fourth dimension British  

noun

1. the dimension of time, which is necessary in addition to three spatial dimensions to specify fully the position and behaviour of a point or particle

2. the concept in science fiction of a dimension in addition to three spatial dimensions, used to explain supernatural phenomena, events, etc

---

fourth dimension Scientific  

/ fôrth /

1. Time regarded as a coordinate dimension. A fourth dimension is required by relativity theory, along with three spatial dimensions, to specify completely the location of any event.

---

Other Word Forms

• fourth-dimensional
  adjective

Etymology

Origin of fourth dimension

First recorded in 1870–75

Example Sentences

Spacetime is just a mathematical object consisting of the three dimensions of space, and time considered as a fourth dimension.

From Science Daily • Dec. 4, 2023

As Diaz puts it, Calder worked in the fourth dimension — time.

From Seattle Times • Nov. 9, 2023

Time melds a fourth dimension to the three we identify as essential to understanding space.

From Los Angeles Times • Nov. 12, 2022

The fourth dimension offers unlimited space in which to unravel even the most complicated knot.

From Washington Post • May 22, 2020

“Ew, no. The fourth dimension is time. This thing has been here for two weeks!”

From "Goodbye Stranger" by Rebecca Stead