The Relationship Between Judaism and Christianity

[nili]

... Subsequently, the official Catholic interpretation of the mention of Jesus' brothers is that they were really his cousins, but that's such a stupid idea to me. As my priest once said during Mass, "They say that they're cousins but Hebrew and Greek have words for 'cousin.'"

Perhaps you could ask your priest to tell you the Hebrew (or Aramaic) word for 'cousin'? I'm aware of nothing other than than, e.g., daughter-of-aunt (בת דודה).

On the other hand, were one to look up the Hebrew word אח in The Brown-Driver-Briggs Hebrew and English Lexicon one would find:

1. brother, born of the same mother (& father)
   
2. indef.= relative
   
3. ...
   

Wikipedia reflects the above when it notes: "The literal translation of the words "brother" and "sister" is an objective problem because there are few quotations and because the words have various meanings in the family of Semitic languages."