1. evidence or facts that show something is true
2. a test copy of printed material for checking errors before final printing
3. the strength of alcoholic drinks, measured as a percentage

1. able to resist or withstand something harmful

1. to make something resistant to damage or harm

Examples

• The fingerprints were proof of his guilt.
• She needed proof of identity to open the account.
• The editor reviewed the proof before publication.
• This vodka is 80 proof.
• The jacket is waterproof and windproof.
• They proofed the basement against flooding.
• The lawyer demanded concrete proof of the allegations.
• The tent fabric is proof against rain and snow.