radiocarbon dating

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A form of radiometric dating used to determine the age of organic remains in ancient objects, such as archaeological specimens, on the basis of the half-life of carbon-14 and a comparison between the ratio of carbon-12 to carbon-14 in a sample of the remains to the known ratio in living organisms.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun physics, archaeology, paleontology A method of estimating the age of an artifact or biological vestige based on the relative amounts of the different isotopes of carbon present in a sample.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a chemical analysis used to determine the age of organic materials based on their content of the radioisotope carbon-14; believed to be reliable up to 40,000 years