root mean square

noun

, Mathematics.

1. the square root of the arithmetic mean of the squares of the numbers in a given set of numbers. : rms

root mean square

noun

1. the square root of the average of the squares of a set of numbers or quantities rms

   the root mean square of 1, 2, and 4 is √[(1² + 2² + 4²)/3] = √7

Word History and Origins

Origin of root mean square¹

First recorded in 1890–95