Which term describes an ongoing competition?

The term that best describes an ongoing competition is "rivalry." This word specifically refers to the state of being in a competitive relationship with others, where two or more parties are constantly vying for superiority or advantage over one another. Rivalries can exist in various contexts, such as sports, business, or academics, and they are characterized by a continuous struggle for dominance, recognition, or achievement.

In contrast, the other terms suggest cooperative or collaborative efforts rather than competition. "Cooperation" implies working together towards common goals, while "collaboration" indicates actively engaging with others to achieve shared outcomes. "Teamwork" also emphasizes collective efforts to accomplish tasks, which stands in stark contrast to the notion of rivalry where competition is at the forefront. Therefore, the essence of ongoing competition is encapsulated in the concept of rivalry, making it the most appropriate choice.