indorsement vs approval

indorsement and approval both are nouns.

Word	Noun	Adjective	Verb	Adverb
indorsement	Yes	No	No	No
approval	Yes	No	No	No

As nouns, approval is a hypernym of indorsement; that is, approval is a word with a broader meaning than indorsement:

Other hypernyms of indorsement include commendation.

indorsement (noun)	approval (noun)
the act of endorsing	the formal act of approving
formal and explicit approval	a message expressing a favorable opinion
a promotional statement (as found on the dust jackets of books)	a feeling of liking something or someone good
a speech seconding a motion	acceptance as satisfactory
a signature that validates something