reversible

capricious fickle fluctuating mercurial protean shifting unpredictable unsettled unstable varying volatile

changeful mutable

agitated commutative convertible fitful flighty fluid impulsive inconstant indecisive irregular irresolute irresponsible kaleidoscopic mobile movable permutable restless revocable skittish spasmodic transformable transitional uncertain unreliable unsteady vacillating vagrant variable variant versatile wavering whimsical

calm constant stable steadfast steady unvarying

certain changeless fixed lasting reliable sure unchangeable undeviating