STABLE, a building in which horses are kept, including the stall in which they stand, furnished with manger and rack, the room in which the harness is kept and attended to, the loft in which the hay and corn are stored, and other accessory rooms, etc. (See HORSE.) This is the current usage, but the word was formerly applied, as was the Latin stabulum, i.e. standingplace (from stare, to stand), to a stall or enclosure for all kinds of domestic animals, cows, sheep, etc. The adjective " stable," meaning firmly established, comes directly from Latin stabilis, also from stare, to stand.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)