Irir Samaale, the oldest common ancestor of several Somali clans, is generally regarded as the source of the ethnonym Somali. The name "Somali" is, in turn, held to be derived from the words soo and maal, which together mean "go and milk" — a reference to the ubiquitous pastoralism of the Somali people. Another plausible etymology proposes that the term Somali is derived from the Arabic for "wealthy" (dhawamaal), again referring to Somali riches in livestock.