Unloose means to untie something, to let it loose, to set it free. You unloose a knot, unloose a rope, unloose a horse from its post. It also gets used for letting something out that was being held back — to unloose a torrent of words, to unloose a flood of anger. The odd thing about this word, and it is worth telling your students because it looks like a mistake, is that 'unloose' and 'loose' mean the same thing. Normally 'un-' reverses a word, so you would expect unloose to mean 'tie up'. It does not. That is because the 'un-' here is an old strengthening prefix rather than a reversing one — it makes the loosening stronger, not opposite. English has a few of these oddities. The word is old-fashioned and literary; the Bible line 'whose shoes I am not worthy to unloose' is where many people have met it. In ordinary modern English, use 'untie', 'undo', 'loosen', or 'let go of'. You will also see 'unloosen', which is even stranger and means the same thing again.

解開、鬆開、放開（古老書面用法，現在多說 untie 或 loosen）