A respirator is a device that helps someone breathe or protects them from breathing in dangerous substances.

In hospitals, respirators are machines that pump air into and out of a patient's lungs when they can't breathe well enough on their own. These life-saving machines take over the work of breathing during serious illness or after major surgery, giving the body time to heal. Doctors and nurses carefully monitor patients on respirators, watching to see when they're strong enough to breathe independently again.

The word also means a mask worn to filter out harmful things from the air. Construction workers wear respirators when sanding or working with chemicals that create dangerous dust. Firefighters use respirators with their own air supply when entering smoke-filled buildings. During the COVID-19 pandemic, healthcare workers wore special respirators, such as N95 masks, to protect themselves from breathing in virus particles while treating sick patients.

The key idea is protection or assistance with breathing. Whether it's a machine breathing for someone who can't, or a mask filtering dangerous particles from the air someone inhales, a respirator helps keep lungs safe and functioning.