a supposed species of prehistoric human presumed on the basis of skull fragments found in Piltdown (Sussex, England) about 1911 and exposed as a hoax in 1953
See Piltdown man in American Heritage Dictionary 4
(pĭltˈdounˌ)
noun
A supposed early species of human postulated from a skull allegedly found in a gravel bed in about 1912 but determined in 1953 to be a fake constructed from a human cranium and the jawbone of an ape.