The E-flat dominant seventh flat five chord (abbreviated "Eb7(b5) chord") is a four-note chord consisting of the notes E♭, G, B♭♭, and D♭. The chord is formed by lowering the fifth of a E-flat dominant seventh chord a half step.
E-flat dominant seventh flat five chord
E♭ G B♭♭ D♭
1 3 ♭5 ♭7
tetrad (four-note chord)