strontium 90 -- (a radioactive isotope of strontium (with the mass number 90) that is present in the fallout from nuclear explosions; can be assimilated like calcium into bones)
dictionary, definition of, free online dictionary, online dictionary, English dictionary, dict, diction, dictonary, glossary, define, definitions, meaning, word of the day, spelling, pronunciation, dictio, dictiona, dic, dicti, dictionar