Jazzy septet?

• Snow White's Dwarfs, e.g.
• Boss welcomes training group
• Water polo team, e.g
• Quintet plus two
• Group of seven in gym detained by principal
• Disney's dwarfs, e.g.
• Series of seven

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Heptad \Hep"tad\, n. [L. heptas the number seven. Gr. ?, ?, fr. "epta` seven.] (Chem.) An atom which has a valence of seven, and which can be theoretically combined with, substituted for, or replaced by, seven monad atoms or radicals; as, iodine is a heptad ...

Wiktionary Word definitions in Wiktionary
n. a group of seven things