Black vomit

1. A copious vomiting of dark-colored matter; or the substance so discharged; — one of the most fatal symptoms in yellow fever.

The word meanings were obtained from OPTED(The Online Plain Text English Dictionary), which is based on “The Project Gutenberg Etext of Webster’s Unabridged Dictionary” which is in turn based on the 1913 US Webster’s Unabridged Dictionary (See Project Gutenburg), as a text file.