Ada f
English: of uncertain origin, apparently not generally bestowed before the late 18th century. In part, this is a pet form of ADELE (SEE Adele) and ADELAIDE (SEE Adelaide), and so it may go back to a Germanic female personal name, a short form of various compound names with the first element adal noble. Ada was the name of a 7th-century abbess of Saint-Julien-des-Prés at Le Mans. Alternatively, it may represent a variant of ADAH (SEE Adah).
First names dictionary. 2012.