white hat

noun

1

: one who is admirable and honorable

2

: a mark or symbol of goodness

… could use a few more guys in white hats.

—Robert Christgau

3

: a hacker who tests computer systems for possible vulnerabilities so that they can be fixed

These so-called "white hats" will spend days or weeks searching company systems to come up with recommendations for fortifying corporations against … threats.

—Greg Wiles

compare black hat

Word History

Etymology

from the white hats stereotypically worn by law-abiding characters in movie westerns

First Known Use

1965, in the meaning defined at sense 1

Rhymes for white hat

• acrobat
• autocrat
• automat
• bundesrat
• bureaucrat
• butterfat
• caveat
• chemostat
• copycat
• cryostat
• democrat
• diplomat