WordNet (r) 3.0 (2006):

unnilquadium
    n 1: a radioactive transuranic element which has been
         synthesized [syn: rutherfordium, Rf, unnilquadium,
         Unq, element 104, atomic number 104]

The Elements (07Nov00):

unnilquadium
Symbol: Unq
Atomic number: 104
Atomic weight: (261)
Radioactive transactinide element. Expected to have similar chemical
properties to those displayed by hafnium. Rf-260 was discovered by the
Joint Nuclear Research Institute at Dubna (U.S.S.R.) in 1964.
Researchers
at Berkeley discovered Unq-257 and Unq-258 in 1964.