*gwher-

Proto-Indo-European root meaning "to heat, warm."

It forms all or part of: brand; brandish; brandy; brimstone; brindled; forceps; Fornax; fornicate; fornication; fornix; furnace; hypothermia; thermal; thermo-; Thermopylae; Thermos.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit gharmah "heat;" Old Persian Garmapada-, name of the fourth month, corresponding to June/July, from garma- "heat;" Hittite war- "to burn;" Armenian jerm "warm;" Greek thermos "warm;" Latin formus "warm," fornax "oven;" Old Irish fogeir "heated;" Old English bærnan "to kindle."