unstable

a.不稳定的

unsightliness, unsightly, unsinkable, unskilled, unskillful, unsmiling, unsociable, unsocial, unsold, unsolicited, unsolved, unsophisticated, unsound, unsparing, unsparingly, unspeakable, unspeakably, unspoiled, unspoken, unspotted, unsteadily, unsteadiness, unsteady, unstinting, unstintingly, unstop, unstoppable, unstuck, unstudied, unsubstantiated, unsuccessful, unsuitable, unsung, unsure, unsuspecting, unswerving, unsympathetic, untainted, untalented, untangle,