Combined standard uncertainty (Combined standard measurement uncertainty)

Standard uncertainty of a measurement result if this result is obtained from the values of a number of other quantities. It is equal to the positive square root of a sum of terms, where the terms are variances or covariances of these other quantities, weighted according to how the measurement result varies with changes in these quantities. (Abbreviation: u_c)

Reference Volume (and volume-specific, additional or differing definitions to the standard):
VDA Volume 5 Measurement and inspection processes, 3rd, revised edition, July 2021