junior class vs class

junior class and class both are nouns.

Word	Noun	Adjective	Verb	Adverb
junior class	Yes	No	No	No
class	Yes	No	Yes	No

As nouns, class is a hypernym of junior class; that is, class is a word with a broader meaning than junior class:

Other hypernyms of junior class include year.

junior class (noun)	class (noun)
penultimate class in high school or college	education imparted in a series of lessons or meetings
	elegance in dress or behavior
	a collection of things sharing a common attribute
	people having the same social, economic, or educational status
	(biology) a taxonomic group containing one or more orders
	a body of students who are taught together
	a body of students who graduate together
	a league ranked by quality

junior class (verb)	class (verb)
	arrange or order by classes or categories