Keywords: happen, occur
As a Noun
1. Something that takes place or happens. English = happening, event, occurrence.
2. Something that might take place in the future. Formal English = contingency.
3. A situation in which it is possible for you to do something that you want to do. English = opportunity, chance.
4. The action by which something that you could not see before moves to a position where it can be seen. English = appearance.
As a Verb or Adjective
1. To take place without being planned. English = happen, occur.
2. Of something that you could not see before, to move to a position where it can be seen. English = appear.