Ulcerous means covered with ulcers, or having the nature of an ulcer. It is the general, describing word of the family, and it is noticeably more formal and more literary than 'ulcerated'. A doctor examining a patient today says 'ulcerated'; a writer describing a beggar's ulcerous legs, or an old medical text describing an ulcerous condition, uses 'ulcerous'. Notice the difference in what the two words point at. 'Ulcerated' points at a particular place and says it has become an ulcer. 'Ulcerous' points at a thing or a state and says it is ulcer-like, full of ulcers, of that kind. That is why 'ulcerous' also stretches easily into figurative writing — an ulcerous hatred, an ulcerous corner of the city — meaning something festering, sore, spreading and unpleasant. In everyday modern English it is rare, and a student can go a long life without needing to produce it. But it turns up in Shakespeare, in older novels, and in writing that wants a strong, sickly image, so it is worth recognising on the page.

潰瘍的、生滿潰瘍的（形容詞，較文言）。台灣中文多說「潰瘍性的」；文學上引申指「腐爛的、化膿般的」，如「腐爛的恨意」。