A person who generally adheres strictly to the Bible, Scripture, or New Testament. Usually found in Southern states, North Carolina, Florida, Texas, Louisiana, etc., etc.... Bible-Thumpers usually allow themselves to be seen as "God-fearing" Christians, but once they're behind closed doors will talk trash about everyone in their neighborhood. They usually try to shove their beliefs down everyones' throats and hate people who are different (Gays, Jews, Wiccans, etc., etc...).
STAY CLEAR OF THEM. POINT BLANK.
"Hey, I'm going over to Sally's today."
"Oh? I hear her parents are Bible-Thumpers."
"Really? That explains a lot..."
"Watch out. The minute they start preaching about how you're always committing a sin, and that if you don't get saved soon you'll burn in hell, get the fuck out of there."
"Will do, will do."