Science, Tech, Math › Science Daughter Isotope Definition - Chemistry Glossary Share Flipboard Email Print Science Chemistry Chemical Laws Basics Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Chemistry in Everyday Life Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate by Anne Marie Helmenstine, Ph.D. Updated March 06, 2017 Daughter Isotope Definition: The product which remains after an original isotope has undergone radioactive decay. The original isotope is termed the 'parent'. Return to the Chemistry Glossary Index Continue Reading