What does "main diagonal" mean?

The entries of a square matrix from the top left to the bottom right.

What is a synonym for "main diagonal"?

Common synonyms include: diagonal, diagonals, principal diagonal.

noun

noun ·Rare ·Advanced level

Noun

1
The entries of a square matrix from the top left to the bottom right.
"In a diagonal matrix, non-zero elements appear only in the main diagonal."
2
the diagonal of a square matrix running from the upper left entry to the lower right entry wordnet

"In a diagonal matrix, non-zero elements appear only in the main diagonal."