trope   /troʊp/

–noun

1. Rhetoric.
	a. any literary or rhetorical device, as metaphor, metonymy, synecdoche, and irony, that consists in the use of words in other than their literal sense. 
	b. an instance of this. Compare figure of speech.
2. a phrase, sentence, or verse formerly interpolated in a liturgical text to amplify or embellish.
3. (in the philosophy of Santayana) the principle of organization according to which matter moves to form an object during the various stages of its existence.

Origin: 1525–35;  < L tropus  figure in rhetoric < Gk trópos  turn, turning, turn or figure of speech, akin to trépein  to turn.

http://dictionary.reference.com/browse/trope
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trope
 
a combining form meaning “one turned toward” that specified by the initial element ( heliotrope ); also occurring in concrete nouns that correspond to abstract nouns ending in -tropy  or -tropism: allotrope.

Origin: < Gk -tropos; see trope, tropo-

Dictionary.com Unabridged. Based on the Random House Dictionary, © Random House, Inc. 2011. 
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trope  (trəʊp)
 
— n
1. 	rhetoric  a word or expression used in a figurative sense
2. 	an interpolation of words or music into the plainsong settings of the Roman Catholic liturgy
 
[C16: from Latin tropus  figurative use of a word, from Greek tropos  style, turn; related to trepein  to turn]

World English Dictionary
Collins English Dictionary - Complete & Unabridged 10th Edition.