See Indorse, Indorsement.
- Nuttall's Standard dictionary of the English language. By Nuttall, P.Austin. Published 1914. (noun) (n.) (noun)

Usage examples:

Nono had assured them that their father approved of the whole thing, and the proud and yet tender way that Jan was walking with Karin showed that the affair had his full endorsement
- The Golden House by Mrs. Woods Baker
Do whatever you feel is best, and you may depend upon my endorsement of any changes you may see fit to make.
- Our Nervous Friends Illustrating the Mastery of Nervousness by Robert S. Carroll
Furthermore, to no class is the indiscriminate endorsement of the recent course of the South toward Negroes more nauseating than to the best thought of the South.
- The Souls of Black Folk by W. E. B. Du Bois