Orthonormal
Two vectors and are said to be
orthonormal if they are both
orthogonal and
normalized. A set of vectors which are pairwise orthonormal is called an
orthonormal set.
When referring to functions, usually the L²norm is assumed unless otherwise stated, so that two functions and are orthonormal over the interval if

Unfortunately, the word
normal is sometimes used synonymously with
orthogonal.
See also: normalized vector, orthogonal, Lp space.