Using a word or phrase to mean the exact opposite of its litera; or normal meaning
Motif
An often repeated idea or theme in literature.
Satire
A literary tone used to ridicule or make fun of some human vice or weakness, often with the intent of correcting or changing the subject of literary attack.
Symbol
A person place or thing used to represent something else
Theme
The statement about life (a message) a particular work is trying to get a cross to the reader.
Tone
The overall feeling, or effect, created by a writer's use of words.