A poetic line of seven iambic feet used widely in England during the sixteenth century before it was replaced by the pentameter. The heptameter has the advantage of being readily divided in groups of four feet, then three, as often found in ballads.
Editors. "Heptameter". The Literary Encyclopedia. First published 01 November 2001
[http://www.litencyc.com/php/stopics.php?rec=true&UID=503, accessed 01 February 2015.]