| 1. | an excessively or blindly optimistic person. |
| 2. | (often lowercase ) Also, Pol⋅ly⋅an⋅na⋅ish. unreasonably or illogically optimistic: some pollyanna notions about world peace. |

(1913) A children's book by the American author Eleanor H. Porter. The title character is an orphan girl who, despite the difficulties of her life, is always extremely cheerful.
Note: A “Pollyanna” remains excessively sweet-tempered and optimistic even in adversity.