A gray-scale image can be interpreted as a function in two-dimensional space.
For example, the surface of the earth is a two-dimensional curved space.
The map will plot each product (usually in two-dimensional space).
Each node in this tree represents a region of the two-dimensional space.
You have created a two-dimensional space whose dimensions are measured in pounds and years.
If this had been a two-dimensional space, it would have been crowded.
"I started exactly as you see here: with two-dimensional space, and a 2-sphere for the standard fiber."
"In two-dimensional space, you only need one extra dimension to avoid the singularity."
Essentially, the word refers to two-dimensional space, and the art of measuring, respectively.
The image on the right shows a mere two-dimensional space where a number of clusters can be identified.
