Crossword clues for the word: INSIDIOUS The word INSIDIOUS has appeared as an answer to at least 4 crossword clues on different crossword puzzles. Crossword clues for INSIDIOUS Showing 1 to 4 of 4 results Clue(s) Short position with private knowledge, obtaining debt pledges - sneaky! Sneakily dangerous Treacherously sneaky Trying to trap