septi-

1. a combining form meaning “seven,” used in the formation of compound words:

   septilateral.

septi-

¹

combining_form

1. seven

   septivalent

septi-

²

combining_form

1. septum

   septicidal

Word History and Origins

Origin of septi-¹

from Latin septem

Words That Use septi-

What does septi- mean?

Septi– is a combining form used like a prefix meaning “seven.” It is occasionally used in scientific and technical terms. In terms from medical and biological science, septi– denotes “septum,” meaning “a dividing wall or membrane in a plant or animal structure.”

Septi– comes from Latin septem, meaning “seven.” The Greek cognate of septem is heptá, meaning “seven,” which is the source of terms such as heptagon, a seven-sided polygon. To learn more, read our Words That Use article on the combining form hepta-.

Examples of septi-

One example of a scientific term that features the form septi– is septivalent, also known as heptavalent, “having a valence of seven.”

The septi– part of the word here means “seven.” The form -valent means “having a valence,” from Latin valent-, literally meaning “being strong.” Septivalent literally translates to “having a valence of seven.”

What are some words that use the combining form septi-?

• septichord
• septicolored
• septifolious
• septifronted
• septisyllable

What are some other forms that septi– may be commonly confused with?

• semi-
• septico-
• sesqui-

Break it down!

Given the meaning of septi-, what does septisyllable mean?