(aviation) The top of the Earth's atmosphere, from 50,000 ft (the start of the stratosphere) and up (to the edge of the exosphere at 1000 mi); where the effects of exposure to the environment on human life is similar to that of exposure to space; it being physiologically incompatible with human life.

(physiology, neuroscience) An area of the medulla oblongata, located in the area postrema, that receives inputs from blood-borne drugs or hormones, and communicates with other structures in the vomiting center to initiate vomiting.

(programming) In JavaScript, the lines of code preceding the declaration of a variable.

plural of temporal dead zone

plural of upper leaf zone

maps prepared for the purpose of earthquake engineering and based on frequency and intensity of expected earthquakes in different areas

plural of seismic zoning

present participle of zone out

present participle of twilight zone

present participle of friend zone