Wordnet 3.0
NOUN (1)
1.
any of a series of radioactive elements with atomic numbers 89 through 103;
[syn: actinoid, actinide, actinon]
WordNet (r) 3.0 (2006):
actinon
n 1: any of a series of radioactive elements with atomic numbers
89 through 103 [syn: actinoid, actinide, actinon]