Go to 'thermo-' entry Go to 'dino-' entry Go to 'chondro-' entry Go to 'aero-' entry Go to '-logy' entry Go to 'thaumato-' entry Go to 'nano-' entry Go to '-sophy' entry Go to 'bucco-' entry Go to '-ism' entry Go to '-lysis' entry Go to 'galacto-' entry Go to '-anthropy' entry Go to 'pneumo-' entry Go to '-ploitation' entry Go to '-lithic' entry Go to '-sepalous' entry Go to 'onco-' entry Go to '-parous' entry Go to 'dermato-' entry Go to 'multi-' entry Go to 'dodeca-' entry Go to '-zoon' entry Go to 'vermi-' entry Go to 'crystallo-' entry Go to 'biblio-' entry Go to 'eco-' entry Go to 'juxta-' entry Go to 'facio-' entry
Affixes: the building blocks of English
Affixes: the building blocks of English

octo- Also octa-.

Eight; having eight.

[Latin octo or Greek oktō, eight.]

Words in octo- are usually of Latin origin, ones in octa- from Greek. An octopus has eight arms; the month of October was originally the eighth month of the Roman year; an octuple consists of eight parts or things; an octocentenary is the eight-hundredth anniversary of a significant event; an octave is a series of eight notes occupying the interval between (and including) two notes, one being half the frequency of the other; an octagon is a plane figure with eight straight sides and eight angles; an octahedron is a three-dimensional shape having eight plane faces. Octogenarian, a person in their eighties, derives from Latin octoginta, eighty.

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