Ardent. Nobility. French form of the Old German Adalheidis, a compound of 'athal' (noble) and 'haida' (hood). Adelaide, the capital of South Australia, was named after Queen Adelaide, 19th century King William IV's consort. Diminutive of Adeline and Adela: Sweet or pleasant; of the nobility. Noble. From the Old German 'athal' meaning noble. Son of Adam: Man of the red earth.