ulcer

英文解釋：

名詞 ulcer:

1. a circumscribed inflammatory and often suppurating lesion on the skin or an internal mucous surface resulting in necrosis of tissue
   同義詞：ulceration

英文造句：

1. His ulcer has kicked up again.
   他的潰瘍又發病了
2. An ulcer located at the initial point of entry of a pathogen.
   初瘡病原體最初侵入的那點處的潰瘍
3. My mouth has an ulcer.
   我的口腔出現了潰瘍。
4. The old man has a stomach ulcer.
   那個老人得了胃潰瘍。