What is the Greek word for 'Cathar'?

• A. Katharos
• B. Kathar
• C. Cathar
• D. Catharos

Answer: (A)

The idea tested here is how Greek forms a masculine singular noun/adjective from a root meaning "pure." The Greek word καθαρός (katharós) uses the -ος ending that marks masculine singular, giving the transliteration katharos. This stays faithful to the original Greek spelling and pronunciation, using kappa for the initial sound and the -os ending that Greek uses for masculine terms. The term Cathars in English ultimately comes from this root, but as a plural form katharoi meaning "the Pure Ones." So the best rendering of the single Greek word is katharos. The other spellings miss the proper ending or use non-Greek transliteration conventions (like a different initial letter or a form that isn’t the standard masculine singular).