The Collaborative International Dictionary
                    Unburthen
                    
                        
                
                                                                    Unburthen \Un*bur"then\, v. t. [1st pref. un- + burthen.] To unburden; to unload.
Wiktionary
                    unburthen
                    
                        
                
                                                                    vb. (obsolete spelling of unburden English)
Usage examples of "unburthen".
This occasioned him to send for a Confessor from the Carthusian monastery, that he might have an opportunity of unburthening his conscience.
But when Achilles was now sated with grief and had unburthened the bitterness of his sorrow, he left his seat and raised the old man by the hand, in pity for his white hair and beard.