transactinide element [trans-ak-tuh-nahyd, tranz-] Word Origin noun Chemistry, Physics.
- any element having an atomic number higher than 103, the last of the actinide series. These superheavy, radioactive elements are extremely short-lived, and can only be created in the laboratory.
See also transuranic element. Origin of transactinide element First recorded in 1965–70; trans- + actinide British Dictionary definitions for transactinide transactinide noun
- any artificially produced element with an atomic number greater than 103
Word Origin for transactinide C20: from trans- + actinide