octa-, octo-, oct-, octi-, octon-

(Greek > Latin: eight, eighth)

octachord, octochord
1. An eight-stringed musical instrument or any musical instrument with eight strings.
2. A series of eight notes; especially, a musical scale.
octad
octagon
octagonal
octagynous
octahedral
octahedrite
octahedron
octamerous
octameter
octandrous
octandrous, octandrious
In botany, having eight stamens.
octane
octangular (ok-TANG-you-luhr) (adjective) (usually not comparable)
Having eight obvious intersections or junctions: The term octangular may refer to an eight sided geometric figure or a numeric quantity of eight divergent loops.
octant