directional antenna vs aerial

directional antenna and aerial both are nouns.

Word	Noun	Adjective	Verb	Adverb
directional antenna	Yes	No	No	No
aerial	Yes	Yes	No	No

As nouns, aerial is a hypernym of directional antenna; that is, aerial is a word with a broader meaning than directional antenna:

directional antenna: an antenna that transmits or receives signals only in a narrow angle
aerial: an electrical device that sends or receives radio or television signals

Other hypernyms of directional antenna include antenna, transmitting aerial.

directional antenna (noun)	aerial (noun)
an antenna that transmits or receives signals only in a narrow angle	a pass to a receiver downfield from the passer
	an electrical device that sends or receives radio or television signals

directional antenna (adjective)	aerial (adjective)
	existing or living or growing or operating in the air
	characterized by lightness and insubstantiality; as impalpable or intangible as air