Posted on 30th August 2018 by melyn Radyoweythres is the Cornish word for radioactivity Yes, radioactivity in Cornish is radyoweythres Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window) Related Post navigationPrevious post: Lafyl is the Cornish word for lawfulNext post: Digreft is the Cornish word for inexpert