ra ‧ don /ˈreɪdɒn $ -dɑːn/ BrE AmE noun [uncountable]
[ Date: 1900-2000 ; Origin: radium ]
a ↑ radioactive gas that is used in the treatment of diseases such as ↑ cancer . It is a chemical ↑ element : symbol Rn
ra ‧ don /ˈreɪdɒn $ -dɑːn/ BrE AmE noun [uncountable]
[ Date: 1900-2000 ; Origin: radium ]
a ↑ radioactive gas that is used in the treatment of diseases such as ↑ cancer . It is a chemical ↑ element : symbol Rn
Longman Dictionary of Contemporary English. Longman - Словарь современного английского языка. 2012