Two lines of VERSE with similar END-RHYMES. Formally, the couplet is a two-line STANZA with both grammatical structure and idea complete within itself, but the form has gone through numerous adaptations, the most famous of which is HEROIC VERSE. In French literature couplet is sometimes used in the sense of STANZA. It is customary but not essential that the length of each line be the same. Couplets are usually written in octosyllabic and decasyllabic lines.