See also the related category snake.
Adder is not commonly used as a baby boy name. It is not in the top 1000 names.
Baby names that sound like Adder include Adair (English, Gaelic, and Scottish), Adaire (English and Scottish), Adar (Hebrew), Adare (English), Addar, Adear, Adeir, Adhir (Indian), Adir (Hebrew), Adra (Indian), Adri (Indian and Hebrew), Adrie, Aitor (Basque and Spanish), Atheer (Arabic), Athir (Arabic), Atri (Indian), Audr (Scandinavian), Audra, Audree, and Audrew.
† Pronunciation for Adder: AE as in "at (AE.T)" ; D as in "day (D.EY)" ; ER as in "hurt (HH.ER.T)"