Un-tweó

According to the Old English Dictionary:

un-tweó

gen. -tweón; m. Not doubt, certainty :-- Bið untweó (-treo, MS.) ðæt ðǽr Adames cyn cwíþeþ gesárgad there is no doubt that Adam's race will lament afflicted, Exon. Th. 59, 31; Cri. 961. un-tweo