to support, to back, to give one's approval to, especially officially or by signature · to write one's signature on the back of a cheque, or other negotiable instrument, when transferring it to a third party, or cashing it · to give an endorsement
köken: From English endorse, alteration influenced by Medieval Latin indorsare of Middle English endosse, from Old French endosser (“to put on back”), from Latin dossum, alternative form of dorsum (“back”).