"Definition of Biological Death"

Definition:
The permanent end of all life functions in an organism or part of an organism.

Source
WordNet Search - 2.1. Death. Cognitive Science Laboratory. Princeton University http://wordnet.princeton.edu/perl/webwn?s=death

An Alternative Definition
The state of a thermodynamic biosystem in which it cannot get and organize autonomously the energy from the environment.

Source
Nahle M. 2004. Meaning of Death: Biological Death Biology Cabinet. Available at: http://biocab.org/Biological_Death.html