PRINCIPAL DIAGONALprincipal diagonal · English · Reference checkedReferenceOpen English WordNet 2024oewn2024:lemma:PRINCIPAL DIAGONALTier 1Ordinal161Pythagorean89Classical153Reverse298Reverse Reduction100Standard663Final Large663Ordinal168Reduced51Atbash577Isopsephy550Ordinal172Abjad430