Sentence:  In Arabic "zeriba" means any kind of rough and ready fenced enclosure; hence the expression “<WSD>zeriba</WSD> country” applied by some geographers to the northern slope of the Nile-Congo divide, where the Arab traders and slave-hunters had founded numerous palisaded stations long before the establishment of the Egyptian administration in that region. 
Meaning of the word marked with <WSD> tags:  A fence of the type once commonly improvised in northeastern Africa from thornbushes.