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Adjective: unstable (unstabler,unstablest)  ,ún'stey-bul
  1. Highly or violently reactive
    "sensitive and highly unstable compounds"
  2. Affording no ease or reassurance
    - precarious
  3. Suffering from severe mental illness
    "of unstable mind";
    - mentally ill, unsound
  4. Disposed to psychological variability
    "his rather unstable religious convictions"
  5. Subject to change; variable
    "everything was unstable following the coup";
    - fluid
  6. Lacking stability, fixity or firmness
    "unstable political conditions"; "the tower proved to be unstable in the high wind"; "an unstable world economy"

Derived forms: unstabler, unstablest

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

Antonym: stable

Encyclopedia: Unstable