Lewis & Short

pūpus, i, m. [root pu-, to beget; cf.: puer, pubes].

  1. I. A boy, a child, Varr. ap. Non. 156, 22; as a term of endearment, puppet, Suet. Calig. 13 fin.
  2. II. The pupil of the eye (post-class. for pupula and pupilla), Paul. Nol. Carm. 20, 179.