aeroplane vs hydroplane

aeroplane and hydroplane both are nouns.

Word	Noun	Adjective	Verb	Adverb
aeroplane	Yes	No	No	No
hydroplane	Yes	No	Yes	No

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

aeroplane: an aircraft that has a fixed wing and is powered by propellers or jets
hydroplane: an airplane that can land on or take off from water

aeroplane (noun)	hydroplane (noun)
an aircraft that has a fixed wing and is powered by propellers or jets	an airplane that can land on or take off from water
	a speedboat that is equipped with winglike structures that lift it so that it skims the water at high speeds

aeroplane (verb)	hydroplane (verb)
	glide on the water in a hydroplane