What is Cm9 chord?

Explanation: The C minor ninth is a five-note chord. The chord is often abbreviated as Cm9 (alternatively Cmin9). Omissions: Cm9(no3): C – G – Bb – D; Cm9(no5): C – Eb – Bb – D. Theory: The Cm9 chord is constructed with a root, a minor third, a perfect fifth, a minor seventh and a major ninth.