to perform dances, gymnastics, and chants (= special shouts) at a sports event to encourage the crowd to support a particular team

I cheerlead for the basketball team. 我为篮球队当啦啦队。

Why not take cheerleading classes if you want to cheerlead your team at a sporting event? 如果你想在体育比赛中为你的队伍当啦啦队鼓气，为什么不参加啦啦队课程？

to express strong support for a person, organization, or policy

The candidate felt he had to cheerlead for the war. 这位候选人觉得他必须表态支持战争。

We're not here either to cheerlead or vilify a company, but to offer analysis for investors weighing decisions about the stock. 我们来这里不是为了支持或者诋毁一家公司，而是为投资者提供分析，让他们权衡有关该公司股票的决策。