writ vs official document

writ and official document both are nouns.

Word	Noun	Adjective	Verb	Adverb
writ	Yes	No	No	No
official document	Yes	No	No	No

As nouns, official document is a hypernym of writ; that is, official document is a word with a broader meaning than writ:

writ: (law) a legal document issued by a court or judicial officer
official document: (law) a document that states some contractual relationship or grants some right

Other hypernyms of writ include instrument, legal document, legal instrument.

writ (noun)	official document (noun)
(law) a legal document issued by a court or judicial officer	(law) a document that states some contractual relationship or grants some right