Aphthous

Part of speech: adjective

Definitions

1. A descriptor in healthcare for recurring painful lesions found in the oral cavity that can lead to significant discomfort
2. Pertaining to a condition involving frequent painful sores within the mouth lining
3. Describes the presence of painful ulcerations inside the oral cavity that often recur

Etymology: "Aphthous" comes from "aphtha," the medical term for a small ulcer or sore, most often inside the mouth. The Greek "aphtha" meant something like a blister or sore, and English took it over as a technical term for those painful spots, which is why the word for mouth ulcers is itself a Greek borrowing. The ending "-ous" is the familiar English adjective suffix, which passed into English through Old French from Latin "-osus," meaning "full of." Put together, "aphthous" means "full of aphthae," or characterized by such sores. The suffix is the more traditional part of the story. Latin "-osus" had spread widely in Romance languages and in Latin itself, producing countless adjectives such as "famous" and "joyous." English adopted it in the Middle English period, and it has been attached to borrowed Greek and Latin bases ever since. "Aphthous" is a straightforward example of that pattern, with a Greek noun supplying the root and an older Latin-derived suffix supplying the adjective form.