noun, adjective · the physical outer limit or boundary of an object, surface, or area

他小心地走在悬崖的边缘。

noun · a point at which a situation is about to change significantly, often toward something negative like a crisis or disaster

由于经营不善，那家公司已处于破产的边缘。

adjective · being outside the mainstream or central focus; peripheral in importance or status

他在社交圈中处于边缘地位，很少参与核心活动。