[{"word":"radioactivity","phonetics":[],"meanings":[{"partOfSpeech":"noun","definitions":[{"definition":"Spontaneous emission of ionizing radiation as a consequence of a nuclear reaction, or directly from the breakdown of an unstable nucleus.","synonyms":[],"antonyms":[]},{"definition":"The radiation so emitted; including gamma rays, alpha particles, neutrons, electrons, positrons, etc.","synonyms":[],"antonyms":[]}],"synonyms":[],"antonyms":[]}],"license":{"name":"CC BY-SA 3.0","url":"https://creativecommons.org/licenses/by-sa/3.0"},"sourceUrls":["https://en.wiktionary.org/wiki/radioactivity"]}]