Ada \a-da\ as a girl's name is pronounced AY-dah. It is of Old German origin, and the meaning of Ada is "noble". A pet form of Adele and Adelaide, or also possibly a Latinate variant of the biblical Hebrew name Adah meaning "adornment". The name was borne by a seventh-century abbess of Saint Julien des Pr?at Le Mans. Not in common use before the late 18th century.
For more information, see also the related name Adamina.