Wiktionary
oughten
contraction (context colloquial or dialectal English) ought not, oughtn't
Usage examples of "oughten".
He's still young enough so he oughten be too tough, but he'll have all that breachin' and screwin' and sod-pawin' in his blood.
Care oughten be taken not to cut on the north an' west edges of the forests, as the old guard pines will break the wind.