[mass noun](chiefly Medicine & Physiology)the process of becoming dilated (主醫(yī),主生理)擴張 ■the action of dilating a vessel or opening (對容器或開口的)擴張 ■[count noun]a dilated part of a hollow organ or vessel (中空器官或容器的)擴張部分
語源
late Middle English: via Old French from late Latin dilatatio(n-), from the verb dilatare (see dilate)