Crossword clues for the word: GRANTGUSTIN The word GRANTGUSTIN has appeared as an answer to at least 1 crossword clue on different crossword puzzles. Crossword clues for GRANTGUSTIN Showing 1 to 1 of 1 results Clue(s) Former "Glee" actor who plays Barry Allen/The Flash on "The Flash" (2 wds.)