Cbm11 chord

The C-flat minor eleventh chord (abbreviated Cbm11 chord) is a six-note chord consisting of the notes C♭, E♭♭, G♭, B♭♭, D♭, and F♭. The chord is formed by adding an eleventh to the C-flat minor ninth chord.

In practice, the fifth (G♭) is often omitted from the Cbm11 chord to avoid a very dissonant sound, and because it's not always possible to play all notes simultaneously.