In regards to a roller coaster, what does the term "double down" mean?

Question

I'm a newly recruited coaster-junkie and I've heard different terms to describe the specifics of a coaster. I was reading up on a couple of my favorites and noticed one description said: "...with towering hills, double-downs and twists..." What does that mean?

Answer 1

A double down is sharp drop, followed by another sharp drop. Hopefully that helps! Heres some terminology I found

http://themeparks.about.com/cs/coasterbo...