The term 'hideous one' can be broken down into three crossword solutions: CRONE (5 letters), repulser (8 letters), and OGRE (4 letters). A CRONE is an old woman, often seen as a witch in folklore. A repulser is someone or something that causes revulsion or disgust. An OGRE is a large, monstrous creature from European folklore. Together, these three words describe a hideous one, which could be an old woman with a monstrous appearance that causes revulsion.