An Etymological Dictionary of Astronomy and Astrophysics

A prefix meaning “fire, heat, high temperature,” used in the formation of compound words. → pyrheliometer; → pyrometer.

Etymology (EN): From Gk. pyro-, combining form of pyr “fire,” cognate with O.E. fyr, O.N. fürr, M.Du. vuur, Ger. Feuer), from PIE *paewr-;
cf. Mod.Pers. Lori porpor “blazing charcoal,” Gilaki bur, biur “smokeless red fire” (Lori perisk, periska “spark,” Kurd. biriske “spark,” Lârestâni pelita “spark”); Gk. pyr “fire;” Hitt. pahhur “fire;” Skt. pū- “to cleanse.”

Etymology (PE): Âzar, variants âtaš, taš “fire,” from Mid.Pers. âtaxš, âtur “fire;” Av. ātar-, āθr- “fire,” singular nominative ātarš-; O.Pers. ātar- “fire;” Av. āθaurvan- “fire priest;” Skt. átharvan- “fire priest;” cf. L. ater “black” (“blackened by fire”); Arm. airem “burns;” Serb. vatra “fire;” PIE base *āter- “fire.”