breathing apparatus

noun breathing apparatuses

1. A device that allows a person to breathe in environments that are dangerous, harmful, or in which it is difficult to breathe. The firefighters put on breathing apparatus and managed to find the injured. In one case, they were almost too late - one of the bystanders who had helped with the initial rescue attempts had been reported missing. They were later found unconscious, having been overcome by the fumes.
2. uncommon The respiratory system of a person or animal.