Third inversion
The third inversion of a seventh chord is the voicing in which the seventh of the chord is the bass note. In the third inversion of a G seventh chord">seventh (chord)">seventh chord, the bass note is F—the seventh of the chord—with the root, third, and fifth above it, forming the intervals of a second, fourth, and sixth above F, respectively. In figured bass, it is referred to as a chord.
According to The American History and Encyclopedia of Music:
Note that any voicing above the bass is allowed. A third inversion chord must have the seventh chord factor in the bass, but it may have any arrangement of the root, third, and fifth above that, including doubled notes, compound intervals, and omission