Described as an animal of great ferocity and strength (Numbers 23:22, R.V., "wild ox, " marg., "ox-antelope;24:8; Isaiah 34:7, R.V., "wild oxen"), and untamable (Job 39:9). It was in reality a two-horned animal; but the exact reference of the word so rendered (reem) is doubtful. Some have supposed it to be the buffalo; others, the white antelope, called by the Arabs rim. Most probably, however, the word denotes the Bos primigenius ("primitive ox"), which is now extinct all over the world. This was the auerochs of the Germans, and the urus described by Caesar (Galatians Bel., vi.28) as inhabiting the Hercynian forest. The word thus rendered has been found in an Assyrian inscription written over the wild ox or bison, which some also suppose to be the animal intended (Comp. Deuteronomy 33:17; Psalm 22:21; 29:6; 92:10).

Noah Webster's New International Dictionary of the English Language

1. (n.) A fabulous animal with one horn; the monoceros; -- often represented in heraldry as a supporter.

2. (n.) A two-horned animal of some unknown kind, so called in the Authorized Version of the Scriptures.

3. (n.) Any large beetle having a hornlike prominence on the head or prothorax.

4. (n.) The larva of a unicorn moth.

5. (n.) The kamichi; -- called also unicorn bird.

6. (n.) A howitzer.