ce|si|um

ce|si|um «SEE zee uhm, SEE see-», noun.

a soft, silvery metallic chemical element that occurs as a minute part of various minerals. It is one of the alkali metals and is highly electropositive. Scientists use the rate of vibration of cesium atoms as a standard for measuring time. Cesium is also used in photoelectric cells. Also, caesium.

╂[< New Latin caesium, neuter of Latin caesius bluish-gray]