Ok, so I looked it up, and apparently it's when you hire a group of girls to encourage your team. They do acrobatics and chant slogans. So your american teams are so bad that you need to pay someone to cheer them on, because the audience wouldn't? Wow.
(I live in England. We don't have 'cheerleading' because your audience would encourage us and sing our praises for free.)
(No offense.)