What is the meaning of Unicorn?

A mythical horse, widely believed to exist until the 17th century, with a single, straight, spiraled horn projecting from its forehead.

In various Bible translations, used to render the Latin unicornis or rhinoceros (representing Hebrew רְאֵם): a reem or wild ox.

Certain animals:

1. Any large beetle having a horn-like prominence on the head or prothorax, especially the Hercules beetle, Dynastes tityus.
2. A caterpillar, Schizura unicornis, with a large thorn-like spine on the back near its head.
3. The kamichi, or unicorn bird.
4. A Siberian unicorn, †Elasmotherium sibiricum.
5. An Asian unicorn, or saola, Pseudoryx nghetinhensis.

Any large beetle having a horn-like prominence on the head or prothorax, especially the Hercules beetle, Dynastes tityus.

A caterpillar, Schizura unicornis, with a large thorn-like spine on the back near its head.

The kamichi, or unicorn bird.

A Siberian unicorn, †Elasmotherium sibiricum.

An Asian unicorn, or saola, Pseudoryx nghetinhensis.

A howitzer.

Someone or something that is rare and hard to find.

A single, usually bisexual woman who participates in swinging or polyamory.

A person with multidisciplinary expertise, especially a laundry list of three or more skills in a young field such as UX design or data science (e.g., domain knowledge, statistics, and software engineering).

A startup company whose valuation has exceeded one billion U.S. dollars, which is solely backed by venture capitalists, and which has yet to have an IPO.

A fan with serious aspirations to become romantically involved with a VTuber (i.e., the streamer behind the avatar).

Being many (especially pastel) colours; multicoloured.

A 15th-century Scottish gold coin worth 18 shillings, bearing the image of a unicorn.

To participate in a sexual threesome as a bisexual addition to an established heterosexual couple.

To exceed a valuation of one billion U.S. dollars, while solely backed by venture capitalists.

Having one horn.

(Can we verify this sense?) Rare and hard to find.

unicorn

alternative form of unicorne

one-horned

Source: wiktionary.org