From Late Latin, meaning ‘white’. The colour was associated in Christian imagery with purity and salvation (see Revelation 3:4 ‘thou hast a few names even in Sardis which have not defiled their garments; and they shall walk with me in white: for they are worthy’). This was the name of several early saints, including a woman supposedly cured by St Peter himself.
English (very common in England, especially in the south Midlands, and in Wales) and German (especially northwestern Germany): patronymic from the personal name Adam. In the U.S. this form has absorbed many patronymics and other derivatives of Adam in languages other than English. (For forms, see Hanks and Hodges 1988.)