lion vs Panthera leo

lion and Panthera leo both are nouns.

Word	Noun	Adjective	Verb	Adverb
lion	Yes	No	No	No
Panthera leo	Yes	No	No	No

As nouns, lion and Panthera leo are synonyms defined as:

lion and Panthera leo: large gregarious predatory feline of Africa and India having a tawny coat with a shaggy mane in the male

Other synonyms of lion include king of beasts.

lion (noun)	Panthera leo (noun)
large gregarious predatory feline of Africa and India having a tawny coat with a shaggy mane in the male	large gregarious predatory feline of Africa and India having a tawny coat with a shaggy mane in the male
a celebrity who is lionized (much sought after)