noun Date: 1936 a heavy radioactive isotope of carbon of mass number 14 used especially in tracer studies and in dating old materials (as archaeological and geological specimens)
CARBON 14
Meaning of CARBON 14 in English
Merriam Webster. Explanatory English dictionary Merriam Webster. Толковый словарь английского языка Мерриам-Уэбстер. 2012