Noun

1. The distance between two points defined as the square root of the sum of the squares of the differences between the corresponding coordinates of the points; for example, in two-dimensional Euclidean geometry, the Euclidean distance between two points a = (a_x, a_y) and b = (b_x, b_y) is defined as:
   

$d(\backslash textbf\{a\},\; \backslash textbf\{b\})\; =\; \backslash sqrt\{(\backslash textbf\{a\}\_x\; -\; \backslash textbf\{b\}\_x)^2\; +\; (\backslash textbf\{a\}\_y\; -\; \backslash textbf\{b\}\_y)^2\}$