occur in WordNet English dictionary

1. come to one's mind; suggest itself
   "It occurred to me that we should hire another secretary"; "A great idea then came to her"
   occur  come 
   
2. come to pass
   "What is happening?"; "The meeting took place off without an incidence"; "Nothing occurred that seemed important"
   happen  hap  go on  pass off  occur  pass  fall out  come about  take place 
   
3. to be found to exist
   "sexism occurs in many workplaces"; "precious stones occur in a large area in Brazil"
   occur