Pairs of quartets

• Groups of eights
• Day in Ascot rearranged for groups of eight
• Planets and notes in the musical scale
• Bytes, usually
• Quarterfinal groups, e.g.
• Candles in a menorah, e.g.
• Sets of eight
• Flag football teams

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