Lai is a medieval narrative or lyric poem, usually in short stanzas and often written in octosyllabic couplets. In English discussions, the word can also be used interchangeably with lay, while some sources connect it with the shorter, songlike virelai. Because the term is used inconsistently, it is often best understood through the specific tradition being discussed.
Example
In the old forest, the knight rode on,
following a silver-threaded song;
Each stanza turned like a winding path,
leading him farther, then carrying him along.