The Collaborative International Dictionary of English v.0.48:

Pithecanthropus \Pith`e*can*thro"pus\
   (p[i^]th`[-e]*k[a^]n*thr[=o]"p[u^]s), prop. n. [NL.; Gr.
   pi`qhkos ape + 'a`nqrwpos man.]
   1. A hypothetical genus of primates intermediate between man
      and the anthropoid apes. --Haeckel.
      [Webster 1913 Suppl.]

   2. A genus consisting of an extinct primate (Pithecanthropus
      erectus) apparently intermediate between man and the
      existing anthropoid apes, known from bones first found in
      Java (hence called Java man) in 1891-92, and other bones
      found later. The species was renamed Homo erectus around
      1960. The Javan bones are believed to be from 1.6 to 1.9
      million years old, and include a thigh bone of the human
      type, two molar teeth intermediate between those of man
      and the anthropoids, and the calvaria of the skull,
      indicating a brain capacity of about 900 cubic
      centimeters, and resembling in form that of the
      Neanderthal man. Additional specimens of what are
      considerd as variants of the species have been found in
      China, Africa, and Europe. Homo erectus is currently
      believed to have evolved in Africa from Homo habilis,
      the first member of the genus Homo. Anatomically and
      physiologically, Homo erectus resembles contemporary
      humans except for having a stouter bone structure. Also
      [pl. -thropi], an animal of this genus. --
      Pith`e*can"thrope, n. -- Pith`e*can"thro*poid, a.
      [Webster 1913 Suppl. +PJC]

WordNet (r) 3.0 (2006):

Java man
    n 1: fossil remains found in Java; formerly called
         Pithecanthropus erectus [syn: Java man, Trinil man]