Daily Ancestorabt.
Abt. means "about": the date or age that follows is an estimate, not an exact figure.
Abt. is a genealogist's short form of about. It is used with dates worked out from ages, such as a birth year estimated from a census age. Ca. or c. (circa) means the same thing.
When you see abt. in someone else's tree, ask what the estimate was based on. Census ages could be off by several years, so a birth year marked abt. may need a wide search range.
As seen in a recordEntry in a family group sheet
Jas. Hill, b. abt. 1810, Penn.
How to cite this page
Daily Ancestor. "abt.." Dictionary of Old Record Words. https://dailyancestor.com/dictionary/abbreviations/abt. Last checked 2026-10-01.