wasteland: ground wrecked and emptied until nothing lives on it, and the horror of the people who look at it
This is a rare word. All seven of its appearances sit in prophecies of judgment, and it almost never stands on its own. Four of the five times Ezekiel uses it he sets it right beside the ordinary Hebrew word for desolation (שְׁמָמָה), so the sentence reads roughly "I will make the land a desolation and a waste." The two words mean nearly the same thing, and that is exactly the point: stacking a word next to its own near twin is how Hebrew raises its voice.
Underneath the word is a picture of ground that has been emptied out. A country reaches that state when its people are killed or carried off and no one is left to work the fields. A river valley reaches it when the water fails, the grass dries up, and the green is gone. Either way what is left cannot support life, and there is no one there to care for it.
Once, in Ezekiel 5:15, the word shifts from the ruin itself to the reaction it causes. Jerusalem is to become a reproach and a taunt, a warning and a horror to the nations around her: not merely a wrecked city, but a wrecked city that other people stare at and shudder over. The root behind this word covers both the wreckage and the dread, which is why one Hebrew term can move so easily from the one to the other.