WordNet (r) 3.0 (2006):

californium
    n 1: a radioactive transuranic element; discovered by bombarding
         curium with alpha particles [syn: californium, Cf,
         atomic number 98]

The Elements (07Nov00):

californium
Symbol: Cf
Atomic number: 98
Atomic weight: (249)
Radioactive metallic transuranic element. Belongs to actinoid series.
Cf-251 has a half life of about 700 years. Nine isotopes are known.
Cf-252 is an intense neutron source, which makes it an intense
neutron source and gives it a use in neutron activation analysis
and a possible use as a radiation source in medicine. First produced
by Glenn T. Seaborg and associates in 1950.