- furnace (n.)
- early 13c., from Old French fornais "oven, furnace," figuratively "flame of love" (12c.), from Latin fornacem (nominative fornax) "an oven, kiln," related to fornus/furnus "oven," and to formus "warm," from PIE root *gwher- "warm" (source also of Greek thermos, Old English wearm; see warm (adj.)).
