WordNet (r) 3.0 (2006):

ununhexium
    n 1: a radioactive transuranic element [syn: ununhexium,
         Uuh, element 116, atomic number 116]

The Elements (07Nov00):

ununhexium
Symbol: Uuh
Atomic number: 116
Atmic weight: 293
Ununhexium is the temporary name of a synthetic superheavy element with
the temporary symbol Uuh and atomic number 116.
It is placed as the heaviest member of group 16 (VIA) although a
sufficiently stable isotope is not known at this time to allow chemical
experiments to confirm its position as the heavier homologue to
polonium.
It was first detected in 2000 and since the discovery about 30 atoms of
ununhexium have been produced, either directly or as a decay product of
ununoctium, and are associated with decays from the four neighbouring
isotopes with masses 290.293. The most stable isotope to date is Uuh-293
with a half-life of ~60 ms.