To sponsor means to support a person, organization, or event by providing money or resources, usually in exchange for some form of recognition or benefit. Companies sponsor sports teams by paying for their uniforms and equipment, often getting their logo printed on the jerseys in return. A local business might sponsor your school's science fair by donating prize money, and in exchange, their name appears on the program.

The word also applies to people who take responsibility for someone else. When immigrants become US citizens, they often need a sponsor who vouches for them and helps them get established.

You can also sponsor someone's charitable efforts: if your friend runs a marathon to raise money for a cause, you might sponsor her by pledging to donate a certain amount for each mile she completes.

A sponsor (the noun) is the person or organization doing the supporting. During television shows, you might hear “This program is brought to you by our sponsors,” meaning the companies that paid for commercial time. The relationship is usually mutually beneficial: the sponsor provides support, and the sponsored person or event provides visibility or recognition in return.