Definition of Old Fourlegs in English:

Old Fourlegs

noun

informal
  • (A nickname for) the coelacanth, Latimeria chalumnae.

Origin

1950s. From old + four + the plural of leg, with allusion to the former belief, later shown to be unfounded, that the fish walked on its four leg-like fins.

Pronunciation

Old Fourlegs

/ˌəʊl(d) ˈfɔːlɛɡz/