1855, from Latin nosocomium, from Greek nosokomeion, from nosos "disease." Nosocome was a 17c. word for "hospital."
nosocomial nos·o·co·mi·al (nŏs'ə-kō'mē-əl)
Of or relating to a hospital.
Of or being a secondary disorder associated with being treated in a hospital but unrelated to the patient's primary condition.