how to understand the “parson meant person”？
He had firm views upon the respect which was due to the cloth, and it was ridiculous for a churchwarden to
take the chair at a meeting when the Vicar was there.
He reminded Josiah Graves that parson meant person, that is, the vicar was the person of the parish

Question

how to understand the “parson meant person”？
He had firm views upon the respect which  was due to the cloth, and it was ridiculous for a churchwarden to 
take the chair at a meeting when the Vicar was there.
He reminded  Josiah Graves that parson meant person, that is, the vicar was the person of the parish

Answer

I'm not familiar with the selection; however, my opinion is that this person objected to Josiah Graves leading the meeting when his superior, the Vicar, was attending.  The man who objected reminded him that the word "parson" was actually an older form of "person" and that, in the way this selection is written, it appears that being the "person of the parish" indicated a more important figure.  It is confusing, but that is my best guess.