junior high vs lyceum

junior high and lyceum both are nouns.

Word	Noun	Adjective	Verb	Adverb
junior high	Yes	No	No	No
lyceum	Yes	No	No	No

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

junior high: a secondary school usually including 7th and 8th grades
lyceum: a school for students intermediate between elementary school and college; usually grades 9 to 12

Other hypernyms of junior high include Gymnasium, lycee, middle school, secondary school.

junior high (noun)	lyceum (noun)
a secondary school usually including 7th and 8th grades	a public hall for lectures and concerts
	a school for students intermediate between elementary school and college; usually grades 9 to 12