The word trope is a rather older term for Figures of speech. The word is not much used in British English. When it is used nowadays, it is used as a one-word synonym for figure of speech. It was not always so. In this, as in other areas of liguistic material, scholarship has moved on, changing definitions as it goes.
At one point, the orthodox classification of figures of speech was into tropes, or 'figures of meaning', and schemes, or 'figures of sound'. This distinction is hard to make watertight. It is worse when we realise that the great Roman orator Cicero (106-43 BCE) said that tropes should be 'figures of meaning' that only involved one word. Figure was the word to use for those that involved more than one word.