In literary criticism, purple prose is written prose that is so extravagant, ornate, or flowery as to break the flow and draw excessive attention to itself. Purple prose is sensually evocative beyond the requirements of its context. It may also employ certain rhetorical effects such as exaggerated sentiment or pathos in an attempt to manipulate a reader's response.
When it is limited to certain passages, they may be termed purple patches or purple passages; these are often noted as standing out from the rest of the work.
The term purple prose is derived from a reference by the Roman poet Horace (Quintus Horatius Flaccus, 65–8 BC) who wrote in his Ars Poetica (lines 14-21):
Inceptis grauibus plerumque et magna professis purpureus, late qui splendeat, unus et alter
adsuitur pannus, cum lucus et ara Dianae
et properantis aquae per amoenos ambitus agros
aut flumen Rhenum aut pluuius describitur arcus;
sed nunc non erat his locus. Et fortasse cupressum
scis simulare; quid hoc, si fractis enatat exspes
nauibus, aere dato qui pingitur?
"Your opening shows great promise, and yet flashy purple patches; as when describing
a sacred grove, or the altar of Diana,
or a stream meandering through fields,
or the river Rhine, or a rainbow;
but this was not the place for them. If you can realistically render
a cypress tree, would you include one when commissioned to paint
a sailor in the midst of a shipwreck?"