WordNet (r) 3.0 (2006):

francium
    n 1: a radioactive element of the alkali-metal group discovered
         as a disintegration product of actinium [syn: francium,
         Fr, atomic number 87]

The Elements (07Nov00):

francium
Symbol: Fr
Atomic number: 87
Atomic weight: (223)
Radioactive element, belongs to group 1 of the periodic table. Found in
uranium and thorium ores. The 22 known isotopes are all radioactive,
with
the most stable being Fr-223. Its existence was confirmed in 1939 by
Marguerite Perey.