indorser vs signatory

indorser and signatory both are nouns.

Word	Noun	Adjective	Verb	Adverb
indorser	Yes	No	No	No
signatory	Yes	No	No	No

As nouns, signatory is a hypernym of indorser; that is, signatory is a word with a broader meaning than indorser:

indorser: a person who transfers his ownership interest in something by signing a check or negotiable security
signatory: someone who signs and is bound by a document

Other hypernyms of indorser include signer.

indorser (noun)	signatory (noun)
someone who expresses strong approval	someone who signs and is bound by a document
a person who transfers his ownership interest in something by signing a check or negotiable security