1. 口潰瘍：Back Pain背痛 | Canker Sore口潰瘍 | Mucous Congestion黏膜阻塞
2. 鹅口疮：急性假膜型念珠菌炎:acute pseudomembranous candicdiasis | 鹅口疮:canker sore | 坏死性龈口炎:necrotizing gingivitis
3. 口疮：Allergic rhinitis 过敏性鼻炎 | Canker sore 口疮 | Diphtheria 白喉
4. 溃疡的痛处：13 Puzzle out:苦苦思索. | 14 Canker sore:溃疡的痛处. | 15 Chomp:咬牙.
noun
1. an ulceration (especially of the lips or lining of the mouth)
Synonym: canker