mediant

The third tone in a diatonic musical scale, determining the major or minor quality of the tonic chord.

In Gregorian music, one of the principal tones of a mode, situated as nearly as possible midway between the dominant and the final, and ranking next in importance to them.

In modern music, the third tone of the scale. The scale is major or minor according as the mediant is a major or a minor third above the key-note.

The third above the keynote; — so called because it divides the interval between the tonic and dominant into two thirds.

The third degree of the diatonic scale.

A rational number whose numerator is the sum of the numerators of two other given rational numbers and whose denominator is the sum of the denominators of those same two other rational numbers.

(music) the third note of a diatonic scale; midway between the tonic and the dominant