Un-gesewen

According to the Old English Dictionary:

-gesawen;

un-gesewen

adj. Unseen, invisible :-- Ðá ðá ða tungel-wítegan ðone cyning gecyrdon, ðá wearð se steorra him ungesewen, Homl. Th. i. 108, 29. Ðone ungesewenan (invisibilem) engel, Past. 36; Swt. 257, 8. Óðre ungesawene þing mon mót mid áðe gewyrðan, L. O. D. 7; Th. i. 356, 6. un-gesewen