- a combining form occurring in loanwords from Greek and Latin, where it meant “eight” (octagon; octastyle), on this model, used in the formation of compound words, and in chemical terms specialized to mean “having eight atoms” (octavalent).
Origin of octa-
< Greek okta-, combining form of oktṓ eight
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for octa
After this Eosa and the rest that fled, being encouraged by Octa's success, came also, and were admitted to the same favour.
The incautious sovereign having assented to this, Octa and Ebusa arrived with forty ships.
- a variant spelling of okta
- a variant of octo-
Word Origin and History for octa
before vowels oct-, word-forming element meaning "eight," from Greek okta-, okt-, from PIE *okto(u) "eight" (see eight). The variant form octo- often appears in words taken from Latin, but the Greek form is said to be the more common in English.
Online Etymology Dictionary, © 2010 Douglas Harper