Unremitting means going on and on without ever easing off. It is a strong, formal word, and its heart is the idea of never letting up — not for a moment, not even a little. Unremitting rain falls all day and all night. Unremitting pressure never eases. Unremitting pain gives you no good hours. It works with hard, tiring things: unremitting heat, unremitting noise, unremitting criticism, unremitting toil. There is one turn worth knowing: when it goes with effort or hard work, the feeling flips to admiration. "Her unremitting hard work paid off" is a compliment — she never let up either. So the word itself only says "never eases"; whether that is awful or admirable depends on what it is describing. This is a book-and-newspaper word. In speech people say "non-stop", "it just doesn't let up", "day after day". If you write unremitting in a friendly email it will sound like you swallowed a leader column. Compare it with unrelieved: unrelieved says there is no break of a different kind inside the bad thing, while unremitting says the thing never weakens or pauses. They overlap a lot, and honestly many writers use them as if they were the same.

持續不斷、never let up 的那種不間斷；如 unremitting rain（下個不停的雨）、unremitting pressure（壓力從沒鬆過）、unremitting effort（不懈的努力，這裡是褒義）。