Syringa reticulata vs lilac

Syringa reticulata and lilac both are nouns.

Word	Noun	Adjective	Verb	Adverb
Syringa reticulata	Yes	No	No	No
lilac	Yes	Yes	No	No

As nouns, lilac is a hypernym of Syringa reticulata; that is, lilac is a word with a broader meaning than Syringa reticulata:

Syringa reticulata: small tree of Japan having narrow pointed leaves and creamy-white flowers
lilac: any of various plants of the genus Syringa having large panicles of usually fragrant flowers

Syringa reticulata (noun)	lilac (noun)
small tree of Japan having narrow pointed leaves and creamy-white flowers	any of various plants of the genus Syringa having large panicles of usually fragrant flowers

Syringa reticulata (adjective)	lilac (adjective)
	of a pale purple color