Define "fundamentalist."
Don't chicken out.
"I know it when I see it"
I will take a crack at it.... Somebody who believes that all of the bible is true, but some parts are truer than others. While others believe that much of the bible is allegory, they believe that many of Jesus commandments aren't as important as Leviticus 20:13.
They believe that James 2:14 doesn't apply to them, yet get all excited about the part of Leviticus they agree with, but reject the rest. Then they use Paul as further justification for their beliefs while ignoring the fact that James, Peter, John, Mark, Matthew, Luke, and ya know Jesus did not share their emphasis. Not their concern mind you, but their emphasis. They twist the bible into pretzels.
They justify not following the sermon on the mount, and build shiny gold topped domes to justify Jesus, while they walk over his sheep the other 6 days of the week. They don't want to wait for God, so they try to ferment unrest in the mideast so God will hurry up, once the temple is rebuilt in Jerusulem.
If Jesus came back attired as he walked in life, they would shut the door on him if he knocked. They do not with love tell the prostitute, the tax collector, the sick, to follow them into the Lord, but call them vile sinners, to justify their self-righteousness. They are the pharisees, who sell video tapes in the temple, and convince others that they need to send $700 to Pat Robertson in order to find salvation. They do not get the point of the Good Samaritan, because they use the argument of the pharisees and lawyers instead of ministering to the unwashed. Condemning is much more satisfying then getting dirty. They do not act as if Jesus is watching them when they lie on their tax forms, ignore the less fortunate, rebuke others when there is still quite a mightly log in their own eye. They love Paul greater than Christ. They follow Paul's teachings must closer.
But... this is just my opinion.