Definition of: thermoluminescence

(thûr′mō·l′mə·nes′·əns) noun
1. The emission of light from a substance or material under the action of heat.
2. A luminous effect in rock crystals from which electrons displaced by radioactivity have been released at definite temperatures, with or without pressure: sometimes indicative of the age of sedimentary rocks.
—ther′mo·lu′mi·nes′cent adjective