highly or violently reactive; "sensitive and highly unstable compounds"
disposed to psychological variability; "his rather unstable religious convictions"
lacking stability or fixity or firmness; "unstable political conditions"; "the tower proved to be unstable in the high wind"; "an unstable world economy"
vibrating slightly and irregularly; as e.g. with fear or cold or like the leaves of an aspen in a breeze; "a quaking bog"; "the quaking child asked for more"; "quivering leaves of a poplar tree"; "with shaking knees"; "seemed shaky on her feet"; "sparkling light from the shivering crystals of the chandelier"; "trembling hands"