1. The sum or number of seven.

Nuttall's Standard dictionary of the English language By Nuttall, P.Austin

• heptaed,
• heptad,
• geptade,
• beptade,
• neptade,
• jeptade,
• ueptade,
• yeptade,
• hwptade,
• hsptade,
• hdptade,
• bheptade,
• hepptade,
• Heptada,
• heptode,
• Hepatade,
• Heptaide,
• Hepetade,
• Heptdade,
• Hepteda

The adjective form of the word "heptade" is "heptadic".

The plural form of "heptade" is "heptades"

The singular form of the word "Heptade" is "Heptad"