existing in WordNet English dictionary

1. having existence or being or actuality
   "an attempt to refine the existent machinery to make it more efficient"; "much of the beluga caviar existing in the world is found in the Soviet Union and Iran"
   existent  existing 
   
2. presently existing
   "the existing system"
   existing 
   
3. existing in something specified
   "depletion of the oxygen existing in the bloodstream"
   existing