Adjective
1. lacking stability or fixity or firmness;
"unstable political conditions""the tower proved to be unstable in the high wind""an unstable world economy"2. highly or violently reactive;
"sensitive and highly unstable compounds"3. affording no ease or reassurance;
"a precarious truce"4. suffering from severe mental illness;
"of unsound mind"5. disposed to psychological variability;
"his rather unstable religious convictions"6. subject to change; variable;
"a fluid situation fraught with uncertainty""everything was unstable following the coup"