Definition of key man in English:

key man

noun

  • 1A man who plays a leading or important role in a group, an industry, etc.

  • 2US historical A telegraph operator.

Origin

Late 19th century; earliest use found in Congregationalist (Boston, Massachusetts). Probably partly from key + man, and partly from key + man.

Pronunciation

key man

/ˈkiː man/