Sentence:  At first Puddock was reserved, but recollecting that he had been left quite free to tell whom he pleased, he made up his mind to <WSD>unbosom</WSD>; and suggested, for the sake of quiet and a longer conversation, that they should go round by the ferry. 
Meaning of the word marked with <WSD> tags:  To tell someone about (one's troubles), and thus obtain relief.