The Collaborative International Dictionary of English v.0.48:
Stable \Sta"ble\ (st[=a]"b'l), a. [OF. estable, F. stable, fr.
L. stabilis, fr. stare to stand. See Stand, v. i. and cf.
1. Firmly established; not easily moved, shaken, or
overthrown; fixed; as, a stable government.
In this region of chance, . . . where nothing is
2. Steady in purpose; constant; firm in resolution; not
easily diverted from a purpose; not fickle or wavering;
as, a man of stable character.
And to her husband ever meek and stable. --Chaucer.
3. Durable; not subject to overthrow or change; firm; as, a
stable foundation; a stable position.
4. (Physics) So placed as to resist forces tending to cause
motion; of such structure as to resist distortion or
molecular or chemical disturbance; -- said of any body or
[Webster 1913 Suppl.]
Stable equilibrium (Mech.), the kind of equilibrium of a
body so placed that if disturbed it returns to its former
position, as in the case when the center of gravity is
below the point or axis of support; -- opposed to
unstable equilibrium, in which the body if disturbed
does not tend to return to its former position, but to
move farther away from it, as in the case of a body
supported at a point below the center of gravity. Cf.
Neutral equilibrium, under Neutral.
Syn: Fixed; steady; constant; abiding; strong; durable; firm.