Not stable. / Having a strong tendency to change. / Fluctuating; not constant. / Fickle. / Unpredictable. / (chemistry) Readily decomposable. / (physics) Radioactive, especially with a short half-life.

(transitive) To release (an animal) from a stable.

Not lodged in a stable.

comparative form of unstable: more unstable

The quality of being unstable; instability

plural of unstableness

Third-person singular simple present indicative form of unstable

In an unstable manner.

(rare) Instability.

present participle of unstable