A chord of the dominant seventh with the ninth added.
position nine in a countable series of things; "going into the ninth they were a run ahead"
within or heading a nine-card holding. [Usage: jack-ninth = nine cards headed by the jack = Jxxxxxxxx.
The interval of nine diatonic degrees.
In music or music theory a ninth is the note nine scale degrees from the root of chord and also the interval between the root and the ninth.