ˈafthə, ˈapthə noun
also ap·tha ˈap-
( plural aph·thae -ˌthē)
Etymology: New Latin, back-formation from Late Latin aphthae, plural, from Greek aphthai, plural of aphtha, perhaps from haptein to fasten, seize, set on fire — more at hapto-
1. : a speck, flake, or blister on the mucous membranes (as in the mouth or gastrointestinal tract or on the lips) characteristic of some diseases (as thrush)
2. : one of the vesicles filled with clear serous fluid that occur in the mouth, on the udder, and in the spaces between the digits of cloven-footed animals in certain diseases — usually used in plural
3. : a disease characterized by aphthae (as foot-and-mouth disease)
• aph·thic -_thik adjective