aphtha

/ˈæfθə/
noun
  1. A small, painful sore inside the mouth, often white or yellow with a red border; a canker sore.
    • She rinsed her mouth with salt water to soothe the aphtha.
    • The dentist said the aphtha would heal on its own in about a week.
    • I got an aphtha on my tongue after biting it while eating.
Synonyms
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