Alligator sinensis vs gator

Alligator sinensis and gator both are nouns.

Word	Noun	Adjective	Verb	Adverb
Alligator sinensis	Yes	No	No	No
gator	Yes	No	No	No

As nouns, gator is a hypernym of Alligator sinensis; that is, gator is a word with a broader meaning than Alligator sinensis:

Alligator sinensis: small alligator of the Yangtze valley of China having unwebbed digits
gator: either of two amphibious reptiles related to crocodiles but with shorter broader snouts

Other hypernyms of Alligator sinensis include alligator.

Alligator sinensis (noun)	gator (noun)
small alligator of the Yangtze valley of China having unwebbed digits	either of two amphibious reptiles related to crocodiles but with shorter broader snouts