A huitain is an eight-line stanza, especially in French poetry. The lines may follow different meters and rhyme patterns, but the form is defined by its eight-line structure. Poets use it to build a compact unit of thought, often with a clear turn or completion by the final line.
Example
Dawn opens softly on the hill,
The orchard lifts its silver shade;
A lone bird tests the air for still,
Then greets the light it helped create.
The pond holds one small piece of sky,
The reeds lean close and whisper low;
By noon, the bells will answer high,
But now the first warm breezes blow.