unstable
Short definition from Wiktionary
Adjective
- Not stable.
- Having a strong tendency to change.
- Fluctuating; not constant.
- Fickle.
- Unpredictable.
- Readily decomposable.
- Radioactive, especially with a short half-life.
Verb
- To release (an animal) from a stable.
We haven’t written up unstable yet: Simple and Standard meanings, examples and a quiz.