as a boys' name is pronounced BAR-klay. It is of Scottish and Old English origin, and the meaning of Barclay is "birch tree meadow". Place name for Berkeley in Gloucestershire, and transferred use of the the Scottish surname, which was taken to Scotland in the 12th century by Walter de Berchelai, who became chamberlain of Scotland in 1165. His descendants became one of the most powerful families in Scotland. This form is most popular in Scotland; Berkeley is more common elsewhere. Barclays is the name of one of the biggest banks in Britain.

http://www.thinkbabynames.com/meaning/1/Barclay