Somnography

Part of speech: noun

Definitions

1. The process of recording brain waves, breathing, heart rate and other body functions while a person sleeps, usually for medical diagnosis
2. A clinical study that monitors physiological signals throughout the night to help identify sleep disorders such as apnea
3. Measuring and charting the body's activity during sleep using electrodes and sensors to assess the quality of rest

Etymology: "Somnus" is the Latin word for sleep, while the ending comes from the Greek "graphein", meaning to write or record. Pairing a Latin first element with a Greek suffix is a common modern practice, so the word is a hybrid coinage rather than something ancient writers used. The ending follows older formations such as "photography" and "biography", where "-graphy" names a process of recording or describing. Here the thing recorded is sleep, so the term refers to measuring and charting what happens while a person rests.