As a Noun: 1. A situation in which it is possible for something to happen, especially a situation which is unexpected and beneficial. English = opportunity, chance. 2. The arrival of someone somewhere, especially unexpectedly. English = appearance. As a Verb or Adjective: 1. To take place without planning and unexpectedly. English = pop up, appear. 2. To be present unexpectedly at a place. English = pop up, appear.