A figurative use of language in which two opposite qualities are conjoined, as in bitter-sweet. Milton's description of hell as having no light, but rather darkness visible is a brilliantly sophisticated example. The following description from Robert Lowell's For the Union Dead is finely intellectual and poetic achievement: “The old South Boston Aquarium stands / In a Sahara of snow now ”
Editors. "Oxymoron". The Literary Encyclopedia. First published 01 November 2001; last revised 30 November -1.
[http://www.litencyc.com/php/stopics.php?rec=true&UID=806, accessed 18 April 2015.]