G Minor 9b5, 1st inversion (Bb in the bass)
Also written as Gm9b5/Bb.
Notes, from the bass up
Bb (bass)DbFAG
The same notes as G Minor 9b5 (Bb, Db, F, A and G), rearranged so Bb is the lowest note. Use it to move between chords with smaller jumps across the keyboard.