A radioactive transuranic metallic element produced by bombarding plutonium with neutrons

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
fermium \fermium\ n. the transuranic element of atomic number 100; symbol Fm. The atomic weight of the most stable isotope, having a half-life of about 80 days, is 257. The first isotope, Fm255 was discovered in 1952 in the debris of a thermonuclear explosion. ...

Douglas Harper's Etymology Dictionary Word definitions in Douglas Harper's Etymology Dictionary
radioactive element, discovered in the debris of a 1952 U.S. nuclear test in the Pacific, named 1955 for Italian-born U.S. physicist Enrico Fermi (1901-1954).

Wikipedia Word definitions in Wikipedia
Fermium is a synthetic element with symbol Fm and atomic number 100. It is a member of the actinide series. It is the heaviest element that can be formed by neutron bombardment of lighter elements, and hence the last element that can be prepared in macroscopic ...

Wiktionary Word definitions in Wiktionary
n. A transuranic chemical element (''symbol'' Fm) with an atomic number of 100.

WordNet Word definitions in WordNet
n. a radioactive transuranic metallic element produced by bombarding plutonium with neutrons [syn: Fm , atomic number 100 ]