English: error
Welsh: cyfeiliornad
Subject: Cyllid ac ystadegau
English definition: In statistics, the amount of deviation from a standard or specification.
Welsh definition: Mewn ystadegau, y gwahaniaeth rhwng gwerth a fesurir neu werth gwirioneddol, a’r gwerth a ragfynegir gan fodel ystadegol.