Niþer-flór

According to the Old English Dictionary:

niþer-flór

f. A lower floor, a room downstairs :-- Gelógode Benedictus hine sylfne on sumes stýpeles úpflóra, and Seruandus gereste hine on þǽre nyðerflóre þæs ylcan stýpeles (in turris inferioribus), Gr. D. 170, 17. Nyðerflóra, 20. niþer-flor