Oxymoron
*An oxymoron (plural oxymora or oxymorons) (from Greek "sharp dull") is a figure of speech that juxtaposes apparently contradictory elements (it is not however a contradiction in terms .Oxymora/Oxymoron appear in a variety of contexts, including inadvertent errors such as ground pilot and literary oxymorons crafted to reveal a paradox.
*The most common form of oxymoron involves an adjective–noun combination of two words.
*As with many other literary and rhetorical devices, oxymorons are used for a variety of purposes. Sometimes they are used to create some sort of drama for the reader or listener, and sometimes they are used to make the person stop and think, whether it's to laugh or to ponder.
Examples:
 "I can resist anything, except temptation." - Oscar Wilde
 "I like a smuggler. He is the only honest thief." - Charles Lamb
Synecdoche
*Synecdoche is closely related to metonymy—a figure of speech in which a term that denotes one thing is used to refer to a related thing. Indeed, synecdoche is sometimes considered a subclass of metonymy. It is more distantly related to other figures of speech, such as metaphor. * *metaphor: changing a word from its literal meaning to one not properly applicable but analogous to it; assertion of identity rather than, as with simile, likeness. * metonymy: substitution of cause for effect, proper name for one of its qualities, etc.

Examples:
 The word “bread” can be used to represent food in general or money (e.g. he is the breadwinner; music is my bread and butter).
 The word “sails” is often used to refer to a whole ship.