promethium n.

in Greek mythology, a demigod (son of the Titan Iapetus) who made man from clay and stole fire from heaven and taught mankind its use, for which he was punished by Zeus by being chained to a rock in the Caucasus, where a vulture came every day and preyed on his liver.

The name is Greek, and anciently was interpreted etymologically as "forethinker, foreseer," from promēthēs "thinking before," from pro "before" (see pro-) + *mēthos, related to mathein "to learn" (from an enlargement of PIE root *men- (1) "to think"). In another view this is folk-etymology, and Watkins suggests the second element is possibly from a base meaning "to steal," also found in Sanskrit mathnati "he steals."

word-forming element in chemistry, used to coin element names, from Latin adjectival suffix -ium (neuter of -ius), which formed metal names in Latin (ferrum "iron," aurum "gold," etc.). In late 18c chemists began to pay attention to the naming of their substances with words that indicate their chemical properties. Berzelius in 1811 proposed forming all element names in Modern Latin. As the names of some recently discovered metallic elements already were in Latin form (uranium, chromium, borium, etc.), the pattern of naming metallic elements in -ium or -um was maintained (in cadmium, lithium, plutonium, etc.; helium is an anomaly).