stabilizer vs tailfin

stabilizer and tailfin both are nouns.

Word	Noun	Adjective	Verb	Adverb
stabilizer	Yes	No	No	No
tailfin	Yes	No	No	No

As nouns, tailfin is a hyponym of stabilizer; that is, tailfin is a word with a more specific, narrower meaning than stabilizer:

stabilizer: airfoil consisting of a device for stabilizing an aircraft
tailfin: a stabilizer that is part of the vertical tail structure of an airplane

Other hyponyms of stabilizer include horizontal tail, tail fin, vertical fin, vertical stabiliser, vertical stabilizer.

stabilizer (noun)	tailfin (noun)
a device for making something stable	a stabilizer that is part of the vertical tail structure of an airplane
airfoil consisting of a device for stabilizing an aircraft	one of a pair of decorations projecting above the rear fenders of an automobile
a chemical that is added to a solution or mixture or suspension to maintain it in a stable or unchanging state