writ vs legal document

writ and legal document both are nouns.

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

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

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

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

writ (noun)	legal 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