An eight line stanza is known as an octave.
In poetry, an octave typically consists of eight lines and can follow various rhyme schemes. It’s often used in sonnets, particularly in the Petrarchan (or Italian) sonnet form, where the first eight lines present a theme or problem. The structure allows for a distinct separation from the following six lines, known as a sestet, which usually serves to resolve or reflect upon the ideas laid out in the octave.