English edit

Etymology edit

cannon +‎ -proof

Adjective edit

cannonproof (comparative more cannonproof, superlative most cannonproof)

  1. impenetrable by cannonballs
    • 1948, Frances Winwar, The Saint and the Devil, page 33:
      It had not helped the duke to build himself a cannonproof stone chamber to sleep in for dread of vengeance after the assassination of Orleans.
    • 1983, Richard J. Hargrove, General John Burgoyne, page 26:
      A cannonproof breastwork, built during the previous war, extended along the beach from the hills to the rocks.