To breathe in and out successively.
To take up oxygen and produce carbon dioxide through oxidation.
To recover one's breath or breathe easily following stress.
To (inhale and) exhale; to breathe.
To use a snorkel.
A snorkel parka.
A retractable tube fitted in diesel-engine submarines to allow sufficient ventilation that the engines may be used at periscope depth.
A hollow tube, held in the mouth, or mounted on and opening into a diving mask, used by swimmers for breathing underwater.