Un-beceás

According to the Old English Dictionary:

un-beceás

adj. Not giving occasion to litigation, indisputable, incontestable :-- Bidde hé ða hond ðe ðæt ierfe hafaþ, ðæt hé him gedó ðone ceáp unbeceásne (that he shew the chattel to be his by incontestable right), L. In. 53; Th. i. 136, 7. un-beceas