n.信號；暗號；信號；跡象；預示；信號燈；指示燈；信號；
vi.發信號；示意；（開轉向燈）示意；發轉彎信號；
vt.向…發信號；示意；（開指示燈）示意；標誌著；是…的標誌；傳達；表達；
adj.出色的；顯著的；重大的
同義詞：indication；?current；?wave；?indicate
雙語例句：
1. Hunger is the body's?signal?that levels of blood sugar are too low.
饑餓是血糖過低時身體發出的信號。
2. We were held up for ages at a?signal?just outside Waterloo.
我們在滑鐵盧站外的信號燈那裏停了很長時間。