# fourth dimension

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.
Origin of fourth dimension
1870-1875
1870-75
Related forms
Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2015.
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Examples from the web for fourth dimension
• In physics, the fifth dimension is a hypothetical dimension which would exist at a right angle to the fourth dimension.
• What's especially interesting is using the fourth dimension to create a third spatial dimension from a two-dimensional image.
• We can think about the fourth dimension and do math int he fourth dimension.
• His slightest movement in the direction of a fourth dimension would put him at once out of three-dimensional space.
• So they wrote: new experiments confirmed existence of the fourth dimension.
• That's is the entire meaning of saying that time is the fourth dimension.
• One suggestion is to consider the relevance of time horizon as a fourth dimension.
• The fourth dimension, time, is used to log the period over which the given forecast takes place.
British Dictionary definitions for fourth dimension

## fourth dimension

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
Derived Forms
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
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fourth dimension in Science
 fourth dimension   (fôrth)    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.
The American Heritage® Science Dictionary
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### Difficulty index for fourth dimension

Few English speakers likely know this word

### Word Value for fourth

12
12
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