Crossword clues for the word: KEYWITNESS The word KEYWITNESS has appeared as an answer to at least 5 crossword clues on different crossword puzzles. Crossword clues for KEYWITNESS Showing 1 to 5 of 5 results Clue(s) Important testimony provider Person who saw how a Vigenere cipher was created? Person with whom the prosecution opens? Provider of crucial testimony Would it not be an open and shut case without him?