Series of eight

• Sets of eight
• Flag football teams
• Pieces of eight?
• Day in Ascot rearranged for groups of eight
• Quartets times two
• White and black pawns, e.g
• Candles in a menorah, e.g.
• Quarterfinal groups
• Planets and notes in the musical scale

Wiktionary Word definitions in Wiktionary
n. (plural of octad English)