Quarterfinal groups, e.g.

• Series of eight
• Bytes, usually
• Pieces of eight?
• White and black pawns, e.g
• Flag football teams
• Candles in a menorah, e.g.
• Planets and notes in the musical scale
• Wild coast hiding first sign of danger for boat crews?
• Groups of eights

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