The story
From Siberian + unicorn, named after this animal's theorized single horn on its head.
Etymology from Wiktionary, CC BY-SA 4.0.
Siberian unicorn
Today it means: An extinct species of rhinoceros, †Elasmotherium sibiricum; it lived in Eastern Europe, Central Asia and East Asia during Late Miocene through to the Late Pleistocene. Full definition →