Definition of tommyknocker in English:

tommyknocker

noun

US
  • (in folklore) a ghost or other supernatural being believed to inhabit mines.

Pronunciation

tommyknocker

/ˈtämēˌnäkər/ /ˈtɑmiˌnɑkər/

Origin

Late 19th century from Tommy, nickname for the given name Thomas + knocker (sense 4).