r rotunda UK /ˌɑː.ɹəʊˈtʌn.də/US /ˌɑɹ.ɹoʊˈtʌn.də/ noun1 •A curved form of the letter r, found in some medieval and fraktur scripts: ⟨ ꝛ ⟩.The distinction between r rotunda and straight r has not been kept in the transcription, as the usage of r rotunda is predictable from the preceding character: r rotunda is used after round letters. — 2017 formsrs rotunda · rs rotundae