Beast, n.
Etymology: [OE. best, beste, OF. beste, F. bête, fr. L. bestia.]
1. Any living creature; an animal; -- including man, insects, etc. [Obs.] Chaucer.
2. Any four-footed animal, that may be used for labor, food, or sport; as, a beast of burden. A righteous man regardeth the life of his beast. Prov. xii. 10.
3. As opposed to man: Any irrational animal.
4. Fig.: A coarse, brutal, filthy, or degraded fellow.
3 more senses
5. A game at cards similar to loo. [Obs.] Wright.
6. A penalty at beast, omber, etc. Hence: To be beasted, to be beaten at beast, omber, etc. Beast royal, the lion. [Obs.] Chaucer.
Syn. -- Beast, Brute. When we use these words in a figurative sense, as applicable to human beings, we think of beasts as mere animals governed by animal appetite; and of brutes as being destitute of reason or moral feeling, and governed by unrestrained passion. Hence we speak of beastly appetites; beastly indulgences, etc.; and of brutal manners; brutal inhumanity; brutal ferocity. So, also, we say of a drunkard, that he first made himself a beast, and then treated his family like a brute.
Shades of meaning
Fernald has no entry of its own for beast; he lists it under animal.
Where he writes about it:
The brute is the animal viewed as dull to all finer feeling; the beast is looked upon as a being of appetites. — from animal
To call a man a brute is to imply that he is unfeeling and cruel; to call him a beast is to indicate that he is vilely sensual. — from animal
We speak of the cruel father as a brute to his children; of the drunkard as making a beast of himself. — from animal
So firmly are these figurative senses established that we now incline to avoid applying brute or beast to any creature, as a horse or dog, for which we have any affection; we prefer in such cases the word animal. — from animal