What does "trope" mean?

Trope: (a) The use of a word or expression in a different sense from that which properly belongs to it; the use of a word or expression as changed from the original signification to another, for the sake of giving life or emphasis to an idea; a figure of speech. (b) The word or expression so used. In his frequent, long, and tedious speeches, it has been said that a trope never passed his lips. Bancroft. Note: Tropes are chiefly of four kinds: metaphor, metonymy, synecdoche, and irony. Some authors make figures the genus, of which trope is a species; others make them different things, defining trope to be a change of sense, and figure to be any ornament, except what becomes so by such change.