diagonalize

[ dahy-ag-uh-nl-ahyz, -ag-nl- ]
/ daɪˈæg ə nlˌaɪz, -ˈæg nl- /

verb (used with object), di·ag·o·nal·ized, di·ag·o·nal·iz·ing.

Mathematics. to transform (a matrix) to a diagonal matrix.
Also especially British, di·ag·o·nal·ise.

Origin of diagonalize

First recorded in 1880–85; diagonal + -ize