tailplane vs airfoil

tailplane and airfoil both are nouns.

Word	Noun	Adjective	Verb	Adverb
tailplane	Yes	No	No	No
airfoil	Yes	No	No	No

As nouns, airfoil is a hypernym of tailplane; that is, airfoil is a word with a broader meaning than tailplane:

tailplane: the horizontal airfoil of an aircraft's tail assembly that is fixed and to which the elevator is hinged
airfoil: a device that provides reactive force when in motion relative to the surrounding air; can lift or control a plane in flight

Other hypernyms of tailplane include aerofoil, control surface, surface.

tailplane (noun)	airfoil (noun)
the horizontal airfoil of an aircraft's tail assembly that is fixed and to which the elevator is hinged	a device that provides reactive force when in motion relative to the surrounding air; can lift or control a plane in flight