From HomoExcelsior

1. unstable weather. 2. unstable vital signs. 3. Fickle. 4. Lacking control of one's emotions; characterized by unpredictable behavior. 5. an unstable ladder. 6. Decomposing readily. 7. Highly or violently reactive. 8. Decaying with relatively short lifetime. Used of subatomic particles. 9. Radioactive.

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