WordNet sense 1 (a unit of radioactivity equal to the amount of a radioactive isotope that decays at the rate of 37,000,000,000 disintegrations per second):

ci

WordNet sense 2 (French physicist; husband of Marie Curie (1859-1906)):

Pierre Curie

WordNet sense 3 (French chemist (born in Poland) who won two Nobel prizes; one (with her husband and Henri Becquerel) for research on radioactivity and another for her discovery of radium and polonium (1867-1934)):

Madame Curie, Marie Curie, Marya Sklodowska