The Collaborative International Dictionary of English v.0.48:

Vomito \Vo*mi"to\, n. [Sp. v['o]mito, fr. L. vomitus. See
   Vomit, n.] (Med.)
   The yellow fever in its worst form, when it is usually
   attended with black vomit. See Black vomit.
   [1913 Webster]