Dictionary
octa-
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).
Also,oct-,octo-.Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.