monomania (mon-<<schwa>>-may-nee-<<schwa>>). Insanity about some particular subject or class of subjects, usu. manifested by a single insane delusion. • A will made by someone suffering from this condition is usu. held valid unless the evidence shows that particular provisions in the will were influenced by the insane delusion. [Cases: Mental Health 3.1.] — monomaniacal, adj. — monomaniac, n.

[Blacks Law 8th]