Definition of Allen wrench in English:

Allen wrench

(also allen wrench)

Pronunciation /ˈalən ˌrenCH/ /ˈælən ˌrɛntʃ/

noun

Trademark ; US
  • An L-shaped metal bar with a hexagonal head at each end, used to turn bolts and screws having hexagonal sockets.

Origin

Early 20th century from the name of the manufacturer, the Allen Manufacturing Company, of Hartford, Connecticut.

Pronunciation

Allen wrench

/ˈalən ˌrenCH/ /ˈælən ˌrɛntʃ/