The F half-diminished seventh chord (abbreviated "Fm7(b5) chord") is a four-note chord consisting of the notes F, A♭, C♭, and E♭. The chord is formed by lowering the fifth of a F minor seventh chord a half step.
F half-diminished seventh chord
F half-diminished chord F minor seventh flat five chord
F A♭ C♭ E♭
1 ♭3 ♭5 ♭7
Fø Fø7 Fm7b5 F–7(b5) Fmi7(b5) Fmin7(b5)
tetrad (four-note chord)