The memo said: His Majesty's Government had no love or use for unendorsed cheques drawn in favour of other people.
Her mandate is unendorsed by those whom she claims to represent.
A man offered me a three- hundred-dollar horse, and wanted to take my simple, unendorsed note for it.
Unless a certificate stands in a customer's name and is unendorsed by him, he has no control over it.
late 14c. endosse "alteration," from Old French endosser (12c.), literally "to put on back," from en- "put on" (see en- (1)) + dos "back," from Latin dossum, variant of dorsum.
Sense of "confirm, approve" (by signing on the back) is recorded in English first in 1847. Assimilated 16c. in form to Medieval Latin indorsare. Related: Endorsed; endorsing.
You can endorse, literally, a cheque or other papers, &, metaphorically, a claim or argument, but to talk of endorsing material things other than papers is a solecism. [Fowler]