octad

A group or sequence of eight.

A system or series of eight.

Having balance equal to that of eight monad atoms, as platinum in the double chlorid of platinum and potassium (K₂PtCl₆).

An atom or radical which has a valence of eight, or is octavalent.

A group of eight things.

a group of eight things

the cardinal number that is the sum of seven and one