Definitions for unstableʌnˈsteɪ bəl
Random House Webster's College Dictionary
not stable; not firm or firmly fixed; unsteady.
liable to change or fluctuate quickly:
an unstable weather pattern.
marked by emotional instability.
unsteadfast; inconstant; wavering.
irregular in movement.
noting chemical compounds that readily decompose or change into other compounds.
Origin of unstable:
lacking stability or fixity or firmness
"unstable political conditions"; "the tower proved to be unstable in the high wind"; "an unstable world economy"
highly or violently reactive
"sensitive and highly unstable compounds"
affording no ease or reassurance
"a precarious truce"
mentally ill, unsound, unstable(adj)
suffering from severe mental illness
"of unsound mind"
disposed to psychological variability
"his rather unstable religious convictions"
subject to change; variable
"a fluid situation fraught with uncertainty"; "everything was unstable following the coup"
Kernerman English Learner's Dictionary
an unstable economy/market; The newly formed democracy is very unstable.
The roof is unstable because of fire damage.
crimes committed by an unstable young man
having a strong tendency to change
fluctuating; not constant
Radioactive, especially with a short half-life
not stable; not firm, fixed, or constant; subject to change or overthrow