grand jury vs jury

grand jury and jury both are nouns.

Word	Noun	Adjective	Verb	Adverb
grand jury	Yes	No	No	No
jury	Yes	No	No	No

As nouns, jury is a hypernym of grand jury; that is, jury is a word with a broader meaning than grand jury:

grand jury: a jury to inquire into accusations of crime and to evaluate the grounds for indictments
jury: a body of citizens sworn to give a true verdict according to the evidence presented in a court of law

grand jury (noun)	jury (noun)
a jury to inquire into accusations of crime and to evaluate the grounds for indictments	a body of citizens sworn to give a true verdict according to the evidence presented in a court of law
	a committee appointed to judge a competition