(chemistry) A negatively charged radical ion.

(chemistry) A positively charged radical ion.

(chemistry) The uncharged radical H₂N^. formally derived from ammonia by removing a hydrogen atom; and any of its derivatives R₂N^.

(chemistry) The uncharged form of an aminoxide derived from hydroxylamines by removal of a proton; their structure is best represented as R₂NO^. <=> R₂N^(.+)-O⁻.

The therapeutic use of ionizing radiation, almost exclusively used for the treatment of malignant disease.

A miniature radio carried aloft (e.g. by an uncrewed balloon, an airdrop from a crewed aircraft, or a sounding rocket) to automatically transmit measurements of the upper air such as the wind speed, pressure, temperature, and relative humidity to a receiving station on the ground.

The radiation presumed to be given off by a black hole by quantum mechanical processes.

(physics, chemistry) Harmful changes in the properties of materials caused by interactions with ionizing radiation.

(physics, biology) The study of the effect of ionizing and nonionizing radiation on biological systems.

(physics, chemistry) The protection of semiconductor devices from the effects of ionizing radiation.