Coxswain's crew, at most

• Arachnid's legs, e.g
• Eight-PArt group
• Two quartets?
• Santa's reindeer, e.g.
• Septet plus one
• Santa's reindeer team, e.g
• The planets, without Pluto
• Pawns, e.g

Wiktionary Word definitions in Wiktionary
n. A group of eight things

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Octad \Oc"tad\, n. [Gr. ?, ?, the number eight.] (Chem.) An atom or radical which has a valence of eight, or is octavalent. A group of eight things.