Ever heard a song a song on the radio and been unable to get it out of your head? It likely got stuck there because of the chorus. In poetry, the chorus is called a refrain.
Coming from an old French word refraindre, meaning 'to repeat', a poetic refrain is a word, group of words, line, or group of lines repeated at specific moments in the poem. In songs, the point of the chorus is to be easily remembered and catchy. In poetry, the refrain's purpose has a little more to it.
The refrain typically appears at the end of the stanza or as its own stanza in between others, though this is not always the case. A refrain can includes rhymes, but it is not necessary. It can also be repeated exactly, or the phrasing can vary slightly. Some poetic forms require a refrain, like a villanelle or a sestina.
Example
The following is a popular example of a poem that uses refrains.
'One Art' by Elizabeth Bishop
The art of losing isn't hard to master;
so many things seem filled with the intent
to be lost that their loss is no disaster.
Lose something every day.
