rotor blade vs aerofoil

rotor blade and aerofoil both are nouns.

Word	Noun	Adjective	Verb	Adverb
rotor blade	Yes	No	No	No
aerofoil	Yes	No	No	No

As nouns, aerofoil is a hypernym of rotor blade; that is, aerofoil is a word with a broader meaning than rotor blade:

rotor blade: the long airfoil that rotates to provide the lift that supports a helicopter in the air
aerofoil: 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 rotor blade include airfoil, control surface, surface.

rotor blade (noun)	aerofoil (noun)
the long airfoil that rotates to provide the lift that supports a helicopter in the air	a device that provides reactive force when in motion relative to the surrounding air; can lift or control a plane in flight