RADIOISOTOPE Scrabble 15 Words With Friends 16 Scrabble letter values: R1A1D2I1O1I1S1O1T1O1P3E1 = 15 Definition noun a radioactive isotope of an element. Examples “produced either naturally or artificially” See all 978 words you can make from RADIOISOTOPE → 12-letter words Words starting with R Words ending with E ← Unscramble different letters