1.a promotional statement (as found on the dust jackets of books);
the author got all his friends to write blurbs for his book
2.a speech seconding a motion;
do I hear a second?
3.formal and explicit approval;
a Democrat usually gets the union's endorsement
4.a signature that validates something;
the cashier would not cash the check without an endorsement
5.the act of endorsing;
a star athlete can make a lot of money from endorsements