Lewis & Short

vĭtellus, i, m. dim. [vitulus].

  1. * I. A little calf, as a term of endearment, Plaut. As. 3, 3, 77.
  2. II. Transf., the yolk of an egg, Cels. 6, 6, 1; Cic. Div. 2, 65, 134; Petr. 33 fin.; Plin. 10, 53, 74, § 148; Hor. S. 2, 4, 14; 2, 4, 57; Mart. 13, 40, 1.
    Called also vĭtellum, i, n., Apic. 4, 1; Varr. ap. Prob. ad Verg. E. 6, 31.