The American Heritage® Dictionary of the English Language, 4th Edition
n. A large, independent, usually nondenominational worship group, especially one formed as an offshoot of a Protestant church. Also called seeker church.
n. A church with an atypically large congregation.
Word Usage
"But living in the buckle of the Bible Belt in the Ozark mountains, I can say unequivocally that something is very disturbing about what I call the megachurch culture prevalent in the south ..."