unsophisticated

a.质朴无华的，天真无邪的

unseemly, unseen, unselfish, unserviceable, unsettle, unsettled, unsettling, unshakable, unshakeable, unsightliness, unsightly, unsinkable, unskilled, unskillful, unsmiling, unsociable, unsocial, unsold, unsolicited, unsolved, unsound, unsparing, unsparingly, unspeakable, unspeakably, unspoiled, unspoken, unspotted, unstable, unsteadily, unsteadiness, unsteady, unstinting, unstintingly, unstop, unstoppable, unstuck, unstudied, unsubstantiated, unsuccessful,