Overview
Zaara is an archaic variant of Sahara, both being English transliterations of the original Arabic word for desert. It is an African region famed for its arid, barren characteristics, and was used by contemporary writers not just as a geographic reference, but also to illustrate the epitome of a dismal wasteland. Modern references to the Sahara as Zaara are very sparse. It generally cannot be found in online dictionaries or encyclopedias, not even as a footnote under the standard spelling. However, a few references can be found in antique books, particularly those regarding the animals of the region and travelogues; and on antique maps, some as recent as 1834.
Literary references
From the chapter on lions in William Smellie's 1781 English translation of Buffon's Histoire Naturelle:
The lions of Mount Atlas, the summit of which is sometimes covered with snow, have neither the courage, the strength, nor the ferocity of the lions of Biledulgerid or of Zaara, whose plains are covered with burning sands. It is chiefly in these fervid deserts that we meet with those terrible lions, who are the dread of travellers, and the scourge of the neighbouring provinces.
In the vast deserts of Zaara, in those that seem to separate two very different races of men, the Negroes and the Moors, in the unpeopled regions that lie about the territories of the Hottentos , and, in general, in all those southern parts of Africa and Asia, which man has disdained to inhabit, the lions are still very numerous, and continue in their natural state.
This is a description of the English Mastiff from the Cynographia Britannica, published in 1800. The reference to attacking "the lord of the savage tribes" means the breed's use as lion-hunters. At the time this was written, lions were commonly referred to as the "king of the beasts":
From Wikipedia (CC BY-SA 4.0).