IMPE'RIOUS, a. [L. imperiosus.]1. Commanding; dictatorial; haughty; arrogant; overbearing; domineering; as an imperious tyrant; an imperious dictator; an imperious man; an imperious temper.2. Commanding; indicating an imperious temper; authoritative; as imperious words.3. Powerful; overbearing; not to be opposed by obstacles; as a man of a vast and imperious mind.4. Commanding; urgent; pressing; as imperious love; imperious circumstances; imperious appetite.5. Authoritative; commanding with rightful authority. The commandment high and imperious in its claims.