legal instrument vs official document

legal instrument and official document both are nouns.

Word	Noun	Adjective	Verb	Adverb
legal instrument	Yes	No	No	No
official document	Yes	No	No	No

As nouns, legal instrument and official document are synonyms defined as:

legal instrument and official document: (law) a document that states some contractual relationship or grants some right

Other synonyms of legal instrument include instrument, legal document.

legal instrument (noun)	official document (noun)
(law) a document that states some contractual relationship or grants some right	(law) a document that states some contractual relationship or grants some right