[Facts] Re: Specific meaning of name element "adal"
The base meaning is "inheriting land", the related words all revolve around inherited land. In OE the cognate terms are Ead "fortune (in both the senses of wealth and luck), (inherited) property", Éðel "patrimony, native land, inheritance" and æðeling "prince" (in a broad sense). By the OE period at least the sense of Adel (OE æðele) was already "noble, eminent, not only by inheritance, but in mind and action".