Where does “floor” come from?

Floor comes from Middle English flor, Old English flōr, and Latin flōrem, the accusative of flōs, ultimately from Proto-Indo-European bʰel-.

floor (English): The interior bottom or surface of a house or...

Definitions

Step	Language	Word	Meaning
1	Middle English	flor	A floor; the bottom surface of a room or...
2	Old English	flōr	floor, pavement, ground; floor, pavement, ground,...
3	Proto-Germanic	flōraz	ground; floor
4	Proto-Indo-European	pleh₂ros	flat; floor
5	Proto-Indo-European	pleh₂-	flat

floor — Etymology, Origin & Word History | Etymology Explorer