Translation:
On 17 May 1785, I, the undersigned parish priest, solemnly married Paul Joseph Martin Defrance, a farmer and legal son of the deceased Jean Defrance and Marie Magdelene Dallier from the parish of Neletteand in the presence of his brother, Jean Louis Defrance, and Charles Antoine Demason and, Marie Therese Gertrude Parment, a legal daughter of the deceased Jean Baptiste Parment, a farmer, and Marie Margueritte Briet of this parish, in the presence of Nicolas Boniface, Henri, and Jean Baptiste Parment, her brothers. The parties obtained a dispensation for third degree of consanguinity from Monseigneur, the Bishop of Amiens. The banns were published on three different Sundays without any opposition or impediment. The engagement was celebrated according to the prescribed form of the Church, and the parties and witnesses signed this present document with us.
Note:
I have removed d'une part …d'autre part.
Laboureur has several translations including husbandman and ploughman.
Assisté also has several translations - witnessed, supported by, in the presence of, assisted by etc.
The phrase 'third degree of consanguinity' refers to a relationship between two people who are related by blood. They are three steps or 'degrees' apart on a consanguinity chart. For example, a person and his uncles and aunts are three degrees of consanguinity apart. You would count from the person to his parent, which is one degree, and then to his grandparent, which is two degrees. From there you'd count down one degree to the person's aunts and uncles. This is a total of three degrees, or the 'third degree of consanguinity.' Another example of the third degree of consanguinity would be between a person and his great-grandchildren. It is one degree from the person to his children, then a second degree to his grandchildren, and a third degree to his great-grandchildren