Meaning of orthonormal

or•tho•nor•mal

Pronunciation: (ôr"thu-nôr'mul), [key]
— adj. Math.
  1. (of a system of functions) normal; normalized.
  2. (of a set of vectors) having the properties that any two vectors are perpendicular and that each vector has a length of one unit.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.