monomania
/ˌmɑnoʊˈmeɪniə/
noun
- An excessive or obsessive interest in a single subject or idea.
- The scientist's monomania about finding a cure drove her to work day and night.
- She had a monomania for cleanliness, scrubbing every surface twice a day.
- His monomania for collecting stamps left him with thousands of albums.
Antonyms