Circumnavigate means to travel around in a big circle. When you circumnavigate the world, will you do it in a boat or a hot air balloon?
Circumnavigate breaks down to circum-, "around," and navigare, "to navigate." It was first used in the era when sailors were trying to find new lands they didn't know about, and so the "around" in question was the trip around the entire earth. We also use circumnavigate to describe going around something that's too hard to go through, like when you circumnavigate the massive crowds in Times Square on New Year's Eve.