wilderness: the open, unsettled, unwatered country beyond the farms and towns, where flocks graze and travelers cross at risk
This is the most common word in the Hebrew Bible for the wild, unfarmed land that lies outside settled life. It is not always pure sand and rock. A wilderness in this sense is land no one has cleared and planted: sometimes barren and waterless, sometimes scattered with enough scrub and seasonal grass to pasture sheep and goats. The single thread holding its uses together is that it is uncultivated open country, not who lives there or how dry it is.
The senses below sort the same land by the role it plays. It can be the bleak, life-threatening expanse a person must survive or pass through. It can be the shepherd's grazing ground, the rough pasture just beyond the village. And again and again it is the specific stretch of desert Israel wandered for forty years, where the nation was tested, fed, and met by God. These are shades of one place, not different places, which is why the same word carries all of them.
Because the wandering loomed so large in Israel's memory, the wilderness also became a charged image: a place of stripping away and of fresh beginning, where God led the people, humbled them, and spoke to them. The prophets reach for that memory both as warning and as promise.