If you surrender, you stop fighting or resisting someone and agree that you have been beaten.

If you surrender something you would rather keep, you give it up or let someone else have it, for example after a struggle.

If you surrender something such as a ticket or your passport, you give it to someone in authority when they ask you to.

You use surrender to refer to someone's attitude or behaviour when they lose the will to resist their feelings or the demands of other people.