Crossword clues for the word: KNEESLAPPER The word KNEESLAPPER has appeared as an answer to at least 6 crossword clues on different crossword puzzles. Crossword clues for KNEESLAPPER Showing 1 to 6 of 6 results Clue(s) "Funny joke!" "Howl, so to speak" Comedian's killer Hilarious joke Really good joke Really good one!