tailfin vs vertical fin

tailfin and vertical fin both are nouns.

Word	Noun	Adjective	Verb	Adverb
tailfin	Yes	No	No	No
vertical fin	Yes	No	No	No

As nouns, tailfin and vertical fin are synonyms defined as:

tailfin and vertical fin: a stabilizer that is part of the vertical tail structure of an airplane

Other synonyms of tailfin include tail fin, vertical stabiliser, vertical stabilizer.

tailfin (noun)	vertical fin (noun)
a stabilizer that is part of the vertical tail structure of an airplane	a stabilizer that is part of the vertical tail structure of an airplane
one of a pair of decorations projecting above the rear fenders of an automobile