1580s, from Prometheus + -an. Before the introduction of modern matches (see lucifer), promethean was the name given (early 19c.) to small glass tubes full of sulphuric acid, surrounded by an inflammable mixture, which ignited when pressed and gave off light.
prologue
prolong
prolongation
prom
promenade
Promethean
Prometheus
promethium
prominence
prominent
promiscuity