Definition of monkey tail in English:

monkey tail

Pronunciation /ˈmʌŋkɪ teɪl/

noun

  • 1Nautical
    rare A rope or lanyard attached to the end of a lever.

  • 2(A nickname for) a type of breech-loading gun first produced by Westley Richards in 1858.

Origin

Early 19th century (in an earlier sense). From monkey + tail.