Abmaj11 chord

The A-flat major eleventh chord (abbreviated Abmaj11 chord) is a six-note chord consisting of the notes A♭, C, E♭, G, B♭, and D♭. The chord is formed by adding an eleventh to the A-flat major ninth chord.

In practice, the fifth (E♭) is often omitted from the Abmaj11 chord to avoid a very dissonant sound, and because it's not always possible to play all notes simultaneously.