[annyokie]

From what I have read, the word "brother" in Aramaic (sp?) is meant to mean "cousin" as well.

It has been proposed that Joseph, being much older than Mary, had children from a previous marriage. Thus, Jesus having a "brother" (half-brother) is not far fetched.

[EternalVigilance]

The New Testament is quite clear that after the birth of Christ, Joseph and Mary had other children.

No need for historical contortions about it.

[Texas_Jarhead]

Jesus did have a half-brother. His name was James.

[Cicero]

There are two issues. As you say, the word translated as "brethren" or "brothers" can mean simply cousins or blood relatives.

The other issue is that although part of the inscription seems genuine, there are problems with the "brother of Jesus" part. It seems to have been added at a different date by another hand. And another expert has said that there are inconsistencies in the spelling.