dilate
/daɪˈleɪt; daɪ`let/ v
1 [I, Tn] (cause sth to) become wider, larger or further open （使某物）扩大, 膨胀, 张大
The pupils of your eyes dilate when you enter a dark room. 进入黑暗的房间时, 瞳孔就扩大.
The horse dilated its nostrils. 那匹马张大了鼻孔.
2 (phr v) dilate on sth (fml 文) speak or write about sth for a long time 详述某事; 铺叙某事
a chapter in which she dilates on the benefits of vegetarianism 她详述素食好处的一章.