Crossword clues for the word: KNOCKEDUP The word KNOCKEDUP has appeared as an answer to at least 2 crossword clues on different crossword puzzles. Crossword clues for KNOCKEDUP Showing 1 to 2 of 2 results Clue(s) 2007 comedy starring Seth Rogen and Katherine Heigl as reluctant parents: 2 wds. Comedy starring Seth Rogen and 47-Across (2 wds.)