Definition of octosyllable in English:

octosyllable

noun

  • A word or line of verse with eight syllables.

    • ‘Meyer's version employs a spare free verse that is very Ibsenish, even though Ibsen composed here in rhymed octosyllables!’

Pronunciation:

octosyllable

/ˈɒktə(ʊ)ˌsɪləb(ə)l/