1) the act of expressing one's true opinion or intention by saying the opposite of one's thoughts in order to make one's remarks forceful, especially by praising and not blaming (irony)

2) an author's explanatory remarks at the beginning of a book; to begin with (preface)

3) (the making of) amusing remarks and answers (repartee)

4) (a kind of) (semi-)liquid preparation served with food to give flavour; rude remarks (often more amusing than annoying) (sauce)