loggerhead vs Caretta caretta

loggerhead and Caretta caretta both are nouns.

Word	Noun	Adjective	Verb	Adverb
loggerhead	Yes	No	No	No
Caretta caretta	Yes	No	No	No

As nouns, loggerhead and Caretta caretta are synonyms defined as:

loggerhead and Caretta caretta: very large carnivorous sea turtle; wide-ranging in warm open seas

Other synonyms of loggerhead include loggerhead turtle.

loggerhead (noun)	Caretta caretta (noun)
very large carnivorous sea turtle; wide-ranging in warm open seas	very large carnivorous sea turtle; wide-ranging in warm open seas
a stupid person; these words are used to express a low opinion of someone's intelligence