n. Journalistic shorthand for reaction or reactions.
The international debate over what to do about Iraq is not only intense at the U.N., it also, as you know, dominates the editorial pages of the world's major dailies.

We're going to sample some of that opinion from around the world as part of a new NBC News segment we are calling "World Reax," "reax" our short form in the news business for reaction.
—Brian Williams, “The News with Brian Williams,” CNBC, March 07, 2003
1986 (earliest)
Here's some reax from Arizona State Coach John Cooper re Akers firing and his name being mentioned as a possible successor:

"If they call me up and want to talk to me, I'll listen. But this is a good job here. I'm happy here. Arizona State is by far the best job I've ever had."
—“Sports News,” The Associated Press, November 29, 1986