Legal terminology is made a bit more understandable when the time period in which it was used is consulted. Does the term infant mean a very young child as thought of today, or a person under the age of twenty-one? What does the term Esquire mean, and is that title carried for the time in office or throughout life?
Find the American and European legal dictionaries needed at DigitalGeorgetown (https://repository.library.georgetown.edu/handle/10822/559416).
Another resource for bygone era non-legal words are Paul Drake’s books, What Did They Mean By That? A Dictionary of Historical and Genealogical Terms Old and New (Westminster, Md.: Heritage Books, 2000), and its sequel.