Definition of "baseballdom"

When the batteries were announced, however, and Herb Pennock of the Boston Red Sox, probably the best pitcher in all baseballdom, was named to twirl for the invading team, we felt we had been tricked.

1949, Mark Raymond Murnane, Ground Swells: Of Sailors, Ships, and Shellac, page 302

Their sensational exploits galvanized baseballdom. Their snow-white knickers and crimson stockings changed uniforms forever.

2015, Jim Bresnahan, Play It Again: Baseball Experts on What Might Have Been, page 14