A large church, usually with stadium seating and large projection screens all over the place. Usually, a megachurch will have a watered-down liturgy consisting mostly of large technological displays and spiritual ballads. There will typically be a sermon afterward with underdeveloped reasoning and theology. A megachurch usually focuses on what the attendee can get out of the experience, rather than what he can give to the experience.
"Man, Charlie has changed. All he does is spout out theological trash and tell us about books we should be buying about how to feel better about ourselves"
"Yea, he started going to that megachurch down the road"