What is Bastarda?

Legal Definition
Bastarda (or bastard or lettretarde in French) was a blackletter script used in France, the Burgundian Netherlands and Germany during the 14th and 15th centuries. The Burgundian variant of script can be seen as the court script of the Dukes of Burgundy and was used to produce some of the most magnificent manuscripts of the 15th century.

The early printers produced regional versions in type which were used especially to print texts in the vernacular languages, more rarely for Latin texts. The earliest bastarda type was produced by Gutenberg in 1454/1455. The main variety was the one used in France, which was also found in Geneva, Antwerp and London. Another local variety was found in the Netherlands; Caxton's first types were a rather poor copy of this. The French lettre bâtarde passed out of use by the mid-16th century but the German variety developed into the national Fraktur type which remained in use until the mid-twentieth century.

British typeface designer Jonathan Barnbrook has designed a contemporary interpretation titled Bastard.
-- Wikipedia
Legal Definition
In old English law. A female .bastard. Fleta, lib. 5, c. 5, § 40.
-- Black's Law Dictionary
Legal Definition
A female bastard.
-- Ballentine's Law Dictionary