A fourteenth century Italian origin, the Ottava Rima is an eight-line stanza with an a-b-a-b-a-b-c-c rhyme scheme. Frances stillman in The Poets Manual and Rhyming Dictonary cites Byrons Don Juan as the best known example in the English Language.
I have written my example of the format, and show it below:
Latent Heat
Words rip from lips – hot with outrage
like swarthe on a lathe streams from the tool
curled steel sheared by a razor sharp edge
waste furiously writhing in a twisted spool
serving no purpose, just conspicuous wastage
handleable only when the latent heat cools.
Only a neighbour disputing a boundary –
using enough energy to fuel an iron foundry.
