death rattle

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A gurgling or rattling sound sometimes made in the throat of a dying person, caused by loss of the cough reflex and passage of the breath through accumulating mucus.

Century Dictionary and Cyclopedia

1. n. A rattling sound sometimes heard in the last labored breathing of a dying person.

Wiktionary

1. n. The raspy or gurgling sound sometimes made by a person as he or she draws in or expels the final breaths in the moments before dying.

GNU Webster's 1913

1. n. a rattling or gurgling in the throat of a dying person.