<p><strong>Noun</strong></p><ul><li>a basis or cause, as for some belief, action, fact, event, etc.: the reasons for declaring war.</li><li>Synonyms: objective, object, aim, end, purpose.</li><li>a statement presented in justification or explanation of a belief or action: I dare you to give me one good reason for quitting school!</li><li>sufficient cause, as produced by a situation that makes an act, feeling, etc., obviously proper or appropriate: After the mess he made of our yard, we have good reason to look for another landscaper.</li><li>Synonyms: rationalization, excuse.</li><li>the mental powers concerned with forming conclusions, judgments, or inferences: Effective leadership requires a person of reason.</li><li>Synonyms: intelligence, mind, intellect, understanding.</li><li>sound judgment; good sense.</li><li>normal or sound powers of mind; sanity.</li><li>Logic: a premise of an argument.</li><li>Philosophy: the faculty or power of acquiring intellectual knowledge, either by direct understanding of first principles or by argument.</li><li>the power of intelligent and dispassionate thought, or of conduct influenced by such thought.</li><li>Kantianism: the faculty by which the ideas of pure reason are created.</li></ul><p><strong>Verb</strong></p><ul><li>(used without object) to think or argue in a logical manner.</li><li>to form conclusions, judgments, or inferences from facts or premises.</li><li>to urge reasons which should determine belief or action.</li><li>Synonyms: persuade.</li><li>(used with object) to think through logically, as a problem (often followed by out).</li><li>to conclude or infer.</li><li>to convince, persuade, etc., by reasoning.</li><li>to support with reasons.</li></ul>