d’Aboville Numbers – A numbering system where the place in the family tree is recorded by each generation’s order in their family.  The furthest back would be 1 (or some other number, if siblings are known), their first child would be 1.1, their fifth would be 1.5, and the fifth’s first child would be 1.5.1, and so on.  Occasionally hyphens are used instead of periods.

Descendancy – Another word for genealogy.  One ancestor’s descendants.

Descendant – The children and grandchildren and etc of an individual.

Diaspora – The movement of a group of people away from an established or ancestral homeland.

Direct Line – The line of descent from ancestor to descendant.

Dowager – A widow who holds title and/or property received from a deceased husband.

Dower – Not to be confused with Dowry.  The portion of a man’s estate allotted to his widow by law.

Dowry – A monetary inheritance given to the husband of a bride at the time the two are engaged or married as the family’s way of contributing to the bride’s new life. 

DAR – Daughters of the American Revolution.  A lineage-based women’s group for those who can claim descent from some of the earliest European immigrants to America, who focus on History, Preservation, Education, and Patriotism.