Epithet is an unusual description of a phenomenon.
Periphrasis is a roundabout way of referring to something by means of several words instead of naming it directly in asingle word or phrase.
one more example: http://www.youtube.com/watch?v=yj8u0Ovgdzg
Euphemism is a substitution of an agreeable or less offensive expression in place of one that may offend or suggest something unpleasant to the listener.
Oxymoron is a rhetorical figure in which incongruous or contradictory terms are combined, as in a deafening silence and a mournful optimist.
Hyperbole is the use of exaggeration as a rhetorical device or figure of speech. It may be used to evoke strong feelings or to create a strong impression, but is not meant to be taken literally.
Information is taken from:
http://www.answers.com/topic/periphrasis
http://en.academic.ru/dic.nsf/enwiki/5552
http://www.answers.com/topic/oxymoron#ixzz2N30KJxpq
http://en.academic.ru/dic.nsf/enwiki/123365