Any four footed animal, which may be used for labor, food or sport; distinguished from fowls, insects, fishes and man; as beasts of burden, beasts of the chase, beasts of the forest. It is usually applied to large animals.

Opposed to man, it signifies any irrational animal, as in the phrase “man and beast.” So wild beast.

Figuratively, a brutal man; a person rude, coarse, filthy, or acting in a manner unworthy of a rational creature.

Agame at cards. Hence to beast.