Such a mineral containing fluorine; especially = "fluorspar".
Early 17th century (in an earlier sense). From classical Latin fluor (in medical context) morbid discharge, flux, (in general context) flow, stream (2nd century ad), in post-classical Latin also menstruation, mineral resembling a gem, such a mineral containing fluorine from fluere to flow + -or.
A substance that fluoresces when struck by high-energy photons; especially one used in fluorography.
1940s; earliest use found in British Patents. From fluor-.