interjection
let's do our best; come on!; we can do this!
Volitional form of 頑張る used as an encouraging interjection. Implies a shared effort or mutual support, like 'let's give it our all' or 'we've got this'.
みんなで頑張ろう!
Let's all do our best!
あと少しだ、頑張ろう。
Just a little more, let's push through.