Hepta is a prefix meaning seven, used to build words related to the number seven. It comes from ancient Greek and appears in scientific and mathematical terms.

A heptagon is a seven-sided shape. A heptathlon is an athletic competition with seven different events, like running, jumping, and throwing. In chemistry, heptane is a molecule with seven carbon atoms linked together.

You'll spot this prefix most often in geometry and science classes. The pattern works like other number prefixes you might know: penta means five (pentagon), hexa means six (hexagon), hepta means seven, and octa means eight (octagon).

While hepta isn't as common as some other number prefixes, recognizing it helps you decode unfamiliar words. When you see hepta at the start of a word, you can make an educated guess that seven of something is involved.