dilator
/daɪˈleɪtə(r)/noun
1- a thing that dilates something, in particular扩张物, 尤指：
1.1
- （亦作dilator muscle）Anatomy a muscle whose contraction dilates an organ or aperture, such as the pupil of the eye【剖】扩张肌。
1.2
- a surgical instrument for dilating a tube or cavity in the body（手术用的）扩张器。
1.3
- a vasodilatory drug血管舒张药物。