v. To write one's signature on the back of (a check, for example) as evidence of the legal transfer of its ownership, especially in return for the cash or credit indicated on its face.v. To place (one's signature), as on a contract, to indicate approval of its contents or terms.v. To acknowledge (receipt of payment) by signing a bill, draft, or other instrument.v. To give approval of or support to, especially by public statement; sanction: endorse a political candidate. See Synonyms at approve.