This definition comes directly from Wikipedia (http://en.wikipedia.org/wiki/Purple_prose):
“Purple prose is a term of literary criticism used to describe passages, or sometimes entire literary works, written in prose so overly extravagant, ornate, or flowery as to break the flow and draw attention to itself. Purple prose is sensually evocative beyond the requirements of its context. It also refers to writing that employs certain rhetorical effects such as exaggerated sentiment or pathos in an attempt to manipulate a reader’s response.
“The term “purple prose” is derived from a reference by the Roman poet Horace. . .Purpureus meant lustrous or dazzling in Horace’s Latin. Purple dye was rare in the Ancient World, with only the wealthiest able to afford it (this is why purple robes and trim came to be associated with the Emperor and, later, European royalty). During the Roman Republic, social climbers would sew purple cloth onto cheaper clothing to give an appearance of wealth. This was regarded as pretentious and gaudy.
“Horace was alluding to this practice, saying that passages marked by ornate rhetoric or elaborate poetic diction were like those “purple patches”, ostentatious and inappropriate. Horace’s advice was that a work should have a stylistic consistency appropriate to its subject matter.”
This makes me want to read Horace. It also makes me want to kill and bury my many darlings.