Word Type

Adjective

Adjective

Verb

The word "unstable" can be used as adjective, adjective and verb.

Word Relationships

Opposites (Antonyms)

stable stable

Derived Terms

emotionally unstable personality disorder unstable equilibrium

Derived From

stable

Context

chemistry physics

Related Terms

instability unstability

Related Terms

change constant decompose fickle fluctuating half life impermanent inconstant instability radioactive strong tendency unpredictable unstability unsteady

Similar Terms

changeable changeable changeful coseismal coseismal coseismic crank cranky cranky explosive explosive impermanent inconstant insane irresolute irresolute reactive reactive rickety rickety rocky rocky seismal seismal seismic shaky temporary tender tippy tipsy tipsy top heavy top-heavy tottering tottering uneasy unsteady volatile volcanic volcanic wobbly wonky

Synonym Network

instable labile mentally ill precarious

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.