protected against the explosive effect of shells or bombs
Word origin
[1860–65; shell + -proof]This word is first recorded in the period 1860–65. Other words that entered Englishat around the same time include: Paleolithic, blind spot, institutionalism, metric system, mutualism-proof is a combining form meaning “resistant, impervious to” that specified by the initialelement. Other words that use the affix -proof include: burglarproof, childproof, waterproof