Nonentity \Non*en"ti*ty\, n.; pl. {Nonentities}. 1. Nonexistence; the negation of being. [1913 Webster] 2. A thing not existing. --South. [1913 Webster] 3. A person or thing of little or no account; an unimportant person; -- usually used as a disparaging term. [Colloq.] [1913 Webster +PJC]