這個字衍生自 nocturne (夜曲；夜景畫)，因此亦意為「夜曲作曲家」或「夜景畫家」。
Last week I received a mailing from Crouse Hospital where I learned about a new type of doctor I had never heard of before — a nocturnist. ...
Nocturnists are surgeons and other specialists who work overnight because they are needed for emergencies at odd hours.
—Trisha Torrey, "Every Patient's Advocate: Hospitals employing many new 'ists'," The Post Standard, April 13, 2010
To bridge the chasm between the day and night shifts, hospitals from Syracuse to Seattle are hiring a new breed of subspecialist called a "nocturnist" — an experienced doctor who works overnight taking care of patients outside the emergency room.
—Sandra G. Boodman, "Shifting the risks at night," The Washington Post, June 7, 2011