The story
- Latin · derived fromr rotunda
- English todayr rotunda
From or representing Latin r rotunda (literally “round ‘r’”). The adjective rotunda is the feminine form of rotundus, inflected to agree with littera (“letter”), elliptically omitted (compare e caudata). The phrase is little attested in Latin, and might have been formed in English, or been borrowed from another language which formed it from those Latin roots.
Etymology from Wiktionary, CC BY-SA 4.0.