petty jury vs jury

petty jury and jury both are nouns.

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

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

petty jury: a jury of 12 to determine the facts and decide the issue in civil or criminal proceedings
jury: a body of citizens sworn to give a true verdict according to the evidence presented in a court of law

petty jury (noun)	jury (noun)
a jury of 12 to determine the facts and decide the issue in civil or criminal proceedings	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