From Brittany or from the land of the Britons
A modern variant of Brittany, referring to the region in northwest France settled by Britons. It ultimately derives from the Latin name Britannia, used by the Romans for the island of Great Britain.
Less common today
Brittony isn't in the latest US Top 1000. It last peaked at #6,782 in 1990.
US births per 5-year period, 1990βpresent (SSA data).