tailplane vs horizontal stabilizer

tailplane and horizontal stabilizer both are nouns.

Word	Noun	Adjective	Verb	Adverb
tailplane	Yes	No	No	No
horizontal stabilizer	Yes	No	No	No

As nouns, tailplane and horizontal stabilizer are synonyms defined as:

tailplane and horizontal stabilizer: the horizontal airfoil of an aircraft's tail assembly that is fixed and to which the elevator is hinged

Other synonyms of tailplane include horizontal stabiliser.

tailplane (noun)	horizontal stabilizer (noun)
the horizontal airfoil of an aircraft's tail assembly that is fixed and to which the elevator is hinged	the horizontal airfoil of an aircraft's tail assembly that is fixed and to which the elevator is hinged