unstable
adj.
lacking stability or fixity or firmness
unstable political conditions|the tower proved to be unstable in the high wind|an unstable world economy
adj.
highly or violently reactive
sensitive and highly unstable compounds
adj.
affording no ease or reassurance
a precarious truce
Synonym: precarious
adj.
suffering from severe mental illness
of unsound mind
Synonym: mentally ill, unsound
adj.
disposed to psychological variability
his rather unstable religious convictions
adj.
subject to change; variable
a fluid situation fraught with uncertainty|everything was unstable following the coup
Synonym: fluid
Antonym: stable