Endorse (verb)

1. To write one's signature on the back of (a check, for example) in order to cash or deposit it.
2. To approve or support publicly.

Origin:

From old french endosser, from en- ("in") + dos ("back"), from latin dorsum ("back").

Examples:

1. The company endorsed the new product.
2. The politician endorsed his rival.
3. The musician endorsed the brand of instruments.
4. He endorsed the check before cashing it.
5. The organization endorsed the candidate.