■ noun
1》 a mythical animal represented as a horse with a single straight horn projecting from its forehead.
↘a heraldic representation of this, with a twisted horn, a deer's feet, a goat's beard, and a lion's tail.
2》 historical a team of three horses arranged two abreast with one leading.
Origin
ME: via OFr. from L. ~is , from uni- 'single' + cornu 'horn', translating Gk monokerōs .