Genealogy kinship terminology has changed throughout history. Kinship terms may not mean what you think they mean. Genealogy research requires an understanding of historical differences in language and customs Genealogy Trek's summary of abbreviations may also be useful

Prior to about 1800, the terms in-law, cousin, grandchildren and orphan were used differently than they are used today.

In-law referred to a legal relationship and could mean step-son or step-daughter or half-brother or half-sister.

Cousin implied a genealogical relationship and generally meant a nephew or a niece.

Grandchildren included grandchildren and great grandchildren.

Orphan was any child whose father was deceased, even if the mother was still living.