What is what does it mean when a man calls a woman a unicorn?

When a man calls a woman a unicorn, it means that she is rare, unique, and special. In a romantic context, it may suggest that she is the perfect partner, someone who possesses all the qualities that he has been searching for in a partner. The term "unicorn" may also imply that she is hard to find, as they are often depicted as mythical creatures in literature and culture. Overall, being called a unicorn by a man is considered a compliment.