Cbm13 chord

The C-flat minor thirteenth chord (abbreviated Cbm13 chord) is a seven-note chord consisting of the notes C♭, E♭♭, G♭, B♭♭, D♭, F♭, and A♭. The chord is formed by adding a thirteenth to the C-flat minor eleventh chord.

In practice, the fifth (G♭) and eleventh (F♭) are often omitted from the Cbm13 chord to avoid a very dissonant sound, and because it's not always possible to play all notes simultaneously.