* Heptagon: A seven-sided polygon.
* Heptachord: A musical scale with seven notes.
* Heptameter: A line of poetry consisting of seven metrical feet.
* Heptad: A group of seven.
* Heptalogy: A series of seven books.
* Heptavalent: Having a valence of seven (in chemistry).
* Hepatitis: Inflammation of the liver.
* Heptachlor: A pesticide (less commonly used today).
Let me know if you'd like to explore any of these words further!