Yakima2Pronunciation: /ˈjakɪmə/Definition of Yakima noun (plural same or Yakimas) 1a member of a North American Indian people of south central Washington State. 2 [mass noun] the language of the Yakima. adjective relating to the Yakima or their language. Origin:the name in Sahaptin (a Salish language)Yakima in other Oxford dictionaries Definition of Yakima in the US English dictionary