Definition of octameter in English:

octameter

Pronunciation /äkˈtamədər/ /ɑkˈtæmədər/

noun

Prosody
  • A line of verse consisting of eight metrical feet.

    ‘Really the only difference is that the terms have been Carrollised and the verse is in octameter instead of pentameter.’
    • ‘It is one of the few poems in English to be written in octameter: sixteen-syllable, or eight-stress, lines.’