cancrum oris

From Latin cancrum ōris, from cancrum (“canker”) and ōris (“of the mouth, face”), genitive singular of ōs (“mouth, face”). The Latin phrase itself is first attested in a source that gives it as a translation of an English common name "mouth canker" or "canker of the mouth".

cancrum oris (uncountable)

1. (pathology) noma, a gangrenous disease of the face

From cancrum (“canker”) and ōris (“of the mouth, face”), genitive singular of ōs (“mouth, face”). First attested in 1649 (see below) in a source that gives it as a translation of an English common name "mouth canker" or "canker of the mouth", and in a context where it is accusative singular (and therefore cancrum could be the masculine accusative singular of cancer). Later authors' interpretation of it as a neuter singular form may be a grammatical blunder.[1][2]

cancrum ōris n (genitive cancrī ōris); second declension

1. (medicine) cancrum oris
   • 1649, Arnold Boate, Observationes medicae de affectibus omissis , (page 26):

     quando epidemice haec labes saevit ob quas causas Anglicum vulgus eam Mouth Canker, aut Canker of the Mouth, id est Cancrum Oris appellat: quod nomen de aliis quoque ulcerosis ac malignis Oris affectibus usurpat.

Second-declension noun (neuter) with an indeclinable portion.