"Aren't" is a contraction of "are not." Synonyms for "aren't" include "are not," "am not," "is not," "was not," "were not," "has not," "have not," "had not," "do not," and "does not." These synonyms are used to express negation or absence, and they are commonly employed in casual and formal communication. While "aren't" is the contraction of "are not," it is important to remember that each of these synonyms can be used to convey the same meaning, but in different contexts and with different nuances. It's essential to choose the right synonym based on the context in which it is being used.