vertical fin vs tailfin

vertical fin and tailfin both are nouns.

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

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

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

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

vertical fin (noun)	tailfin (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