septi-

American  

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

   septilateral.

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septi- ¹ British  

combining form

1. seven

   septivalent

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septi- ² British  

combining form

1. septum

   septicidal

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Usage

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-.

Etymology

Origin of septi-

from Latin septem