A proper noun is a noun that names or references a specific object. In the New Testament proper nouns are nouns that name a specific person or place.
Peter and Jerusalem are both proper nouns. Peter is a proper noun because it is the name of a specific person, and Jerusalem is a proper noun because it names a specific city. The opposite of a proper noun is a common noun. The nouns man and city are both common nouns because they are both general and do not name a specific man or specific city.
|you||will be called||Cephas||which||is translated||Peter|
you will be called Cephas, which is translated as Peter
Note: Both Cephas and Peter are proper nouns because they are names for a specific person. (Cephas is Peter’s name in Aramaic and means “rock.” Peter is the Greek translation of the name Cephas and also means “rock.”)