-proofs, -proofing, -proofed1) COMB in ADJ -proof combines with nouns and verbs to form adjectives which indicate that something cannot be damaged or badly affected by the thing or action mentioned.
...a bomb-proof aircraft...
In a large microwave-proof dish, melt butter for 20 seconds.
...tamper-proof medicine bottles.2) COMB in VB -proof combines with nouns to form verbs which refer to protecting something against being damaged or badly affected by the thing mentioned.
[V n] ...home energy efficiency grants towards the cost of draught-proofing your home.
[V-ed] ...inflation-proofed pensions.
English dictionary. 2008.