Meaning of DUALITY in English
/dooh al"i tee, dyooh-/ , n.
1. a dual state or quality.
2. Math. a symmetry within a mathematical system such that a theorem remains valid if certain objects, relations, or operations are interchanged, as the interchange of points and lines in a plane in projective geometry.
[ 1350-1400; ME dualitie dualitas. See DUAL, -ITY ]
Random House Webster's Unabridged English dictionary. Полный английский словарь Вебстер - Random House . 2012