Festnes
Bosworth & Toller Anglo-Saxon Old English Dictionary - festnes
According to the Old English Dictionary:
-ness, e;
- festnes
- f. A fastness, firmament; firmāmentum :-- Weorc handa his bodaþ festnes [MS. fesnesse] ŏpĕra mănuum ejus annuntiat firmāmentum, Ps. Spl. T. 18, 1.