Clue: Hard to penetrate
Hard to penetrate is a crossword puzzle clue that we have spotted 5 times. There are related clues (shown below).
Referring crossword puzzle answers
Likely related crossword puzzle clues
Recent usage in crossword puzzles:
- Pat Sajak Code Letter - March 5, 2009
- Universal Crossword - Feb. 2, 2006
- USA Today - Oct. 18, 2005
- USA Today - March 16, 2004
- New York Times - Sept. 19, 1979
