coincidence  
noun uk/kəʊˈɪn.sɪ.dəns/ us/koʊˈɪn.sɪ.dəns/
  (SAME TIME)      
 B2 [ C ]同时发生;(尤指令人吃惊的)巧合,碰巧的事 
an occasion when two or more similar things happen at the same time, especially in a way that is unlikely and surprising
  You chose exactly the same wallpaper as us - what a coincidence! 你选的壁纸跟我们的一模一样——真巧! 
 Is it just a coincidence that the wife of the man who ran the competition won first prize? 赢得头等奖的人是竞赛组织者的老婆,这难道仅仅是巧合吗? 
 a series of strange/amazing coincidences 一系列奇怪/令人惊讶的巧合 
 - More examples
 - We hadn't planned to be in France at the same time as Ann and Charles - it was just a happy coincidence.
 - Meeting you here in Rome is a remarkable coincidence.
 - By some extraordinary coincidence, I sat down right opposite your mother in the train.
 - Do you think it was just a coincidence that she chose her own granddaughter's picture for first prize?
 - There were a whole series of spooky coincidences - for example we both married men with the same name and on the same day.
 
  (CHANCE)      
B2 [ U ]偶然的机遇,运气 
chance or luck
  Just by coincidence, I met my old schoolmate again 50 years later. 纯粹是碰巧了,我在50年后又遇到了我的老同学。 
 [ + that ] It was pure/sheer coincidence that I remembered his phone number. 我记住他的电话号码纯属偶然。 
 By some strange coincidence, he was passing the house just when it happened. 事情发生时他碰巧路过这所房子。 
 - More examples
 - We hadn't planned to be in France at the same time as Ann and Charles - it was just a happy coincidence.
 - Meeting you here in Rome is a remarkable coincidence.
 - By some extraordinary coincidence, I sat down right opposite your mother in the train.
 - Do you think it was just a coincidence that she chose her own granddaughter's picture for first prize?
 - There were a whole series of spooky coincidences - for example we both married men with the same name and on the same day.