Definition of middle leg in English:

middle leg

Pronunciation /ˌmɪdl ˈlɛɡ/

noun

  • 1slang A man's penis.

  • 2Entomology
    Either of the middle pair of an insect's legs, between the forelegs and the hind legs.

Origin

Mid 16th century (in an earlier sense). From middle + leg.