Irrationalness refers to the lack of logic or reason in a thought or action. Synonyms for this term include irrationality, illogicality, unreasonableness, absurdity, irrationalism, and senselessness. Irrationality is often associated with behavior that is difficult to understand or explain, such as fear or phobias, anxiety, or compulsive behavior. Illogicality implies that there is no logical basis for a belief or action. Unreasonableness suggests an unwillingness to consider other points of view, while absurdity describes something that is inherently ridiculous or impossible. Irrationalism emphasizes the rejection of reason or the value of emotion or intuition over logic, and senselessness highlights the lack of meaning or purpose in a thought or action.