The Bedford Glossary of Critical and Literary Terms - Ross Murfin 2018
Octave (octet)
Octave (octet): (1) Generally, any eight-line stanza. (2) More specifically, the first part (the first eight lines) of an Italian sonnet. The octave, which follows the rhyme scheme abbaabba, precedes the sestet and may pose a question or dilemma that the sestet answers or resolves.