Sentence:  These differences in turn result from the fact that my Yokuts vocabularies were built up of terms selected mainly to insure unambiguity of English meaning between illiterate informants and myself , within a compact and uniform territorial <WSD>area</WSD> , but that Hoijer 's vocabulary is based on Swadesh 's second glottochronological list which aims at eliminating all items which might be culturally or geographically determined . 
Meaning of the word marked with <WSD> tags:  a particular geographical region of indefinite boundary (usually serving some special purpose or distinguished by its people or culture or geography)