1 随便
free familiar casual passing negligent undress cursive promiscuous glib unceremonious lighthearted unbending shirttail unstuffy shirt-sleeve unstarched hail-fellow hang-loose random arbitrarily dooms familiarity at hazard out of a hat without ceremony and center
2 任意
random arbitrary discretionary facultative ad-lib unselective unprescribed arbitrarily accord out of a hat at option at own sweet will