Neisseria meningitidis

Etymology
Neisseria meningitidis:

neisseria: "Neisser" (named after the bacteriologist Albert Neisser)

meningitidis: "meningitis" (named after the disease "meningitis")

Explanation
The bacteria Neisseria meningitidis was named after the scientist who first discovered the genus (Neisser), and because it is responsible for causing meningitis and meningococcemia (meningitidis).

Synonyms
meningococcus