1) One who's thoughts and resultant behaviors support and are pursuant to the ideology that:
A) The Nation of Israel has a right to exist,
B) As a Jewish state it it so choses, and
C) In peace and harmony with its neighbors
2) One who - either Jew or Gentile - stands in defiance of oppression against Jews and Judaism in any of its forms: mockery, belittlement, violence, defamation, disparagement etc. and et al.
Because I'm a pro-Semite, I will not work with Mel Gibson unless and until he issues a better apology that THAT!
No, you don't have to be Jewish to be a pro-Semite. You just have to be free from bigotry against Jews, that's all.