In French, name Addy means – Diminutive of Adelaide: 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 IVs consort.. Other origins for name Addy include – French, English, German, English, Hebrew. Name Addy is most often used as a girl name or female name.