Crossword clues for the word: ONTOLOGY The word ONTOLOGY has appeared as an answer to at least 5 crossword clues on different crossword puzzles. Crossword clues for ONTOLOGY Showing 1 to 5 of 5 results Clue(s) Branch of metaphysics Branch of metaphysics that deals with nature of reality Branch of metaphysics that deals with the nature of existence Metaphysics subject Study of being