The term "circle tour" refers to a journey or trip which begins and ends at the same place, but follows a circular route. The opposite of this particular term could be a "linear tour," in which a person travels from one point to another without ever retracing their steps. Another antonym of "circle tour" could be a "random tour," which does not follow any specific path or pattern, and instead involves a haphazard exploration of different locations. Similarly, a "one-way tour" would involve traveling in one direction only and not returning to the starting point. Overall, there are many ways to travel and explore the world, and different types of tours can provide unique experiences to suit various preferences.