Unstableness

Unstable Un*sta"ble, a. [Cf. {Instable}.] Not stable; not firm, fixed, or constant; subject to change or overthrow. -- {Un*sta"ble*ness}, n. --Chaucer. [1913 Webster]

{Unstable equilibrium}. See {Stable equilibrium}, under {Stable}. [1913 Webster]