stably - adj.
(stabler, stablest)
1 firmly fixed or established; not easily adjusted, destroyed, or altered (a stable structure; a stable government).
2 firm, resolute; not wavering or fickle (a stable and steadfast friend).
3 Chem. (of a compound) not readily decomposing.
4 Physics (of an isotope) not subject to radioactive decay.

stable equilibrium a state in which a body when disturbed tends to return to equilibrium.

stableness n. stably adv. [ME f. AF stable, OF estable f. L stabilis f. stare stand]