cu·rie / ˈkyoŏrē; kyoŏˈrē/ (abbr.: Ci) • n. (pl. -ries) a unit of radioactivity, corresponding to 3.7 × 10¹⁰ disintegrations per second. ∎  the quantity of radioactive substance that has this amount of activity.

curie (symbol Ci) Unit formerly used to measure the activity of a radioactive substance. Named after Marie Curie, it is defined as that quantity of a radioactive isotope that decays at the rate of 3.7 × 10¹⁰ disintegrations per second. The curie has been replaced by an SI unit, the becquerel (symbol Bq

curie (kewr-ee) n. a former unit for expressing the activity of a radioactive substance. It has been replaced by the becquerel. Symbol: Ci.