to depend on someone or something for a successful result The party is pinning its hopes on its new leader, who is young, good-looking, and very popular.Scientists are pinning their hopes on the high-tech laboratory.
Usage notes: usually said when it is not certain whether something will happen or succeed
to hope that something or someone will help you achieve what you want The party is pinning its hopes on its new leader who is young, good-looking, and very popular with ordinary people.