alkene vs cycloalkene

alkene and cycloalkene both are nouns.

Word	Noun	Adjective	Verb	Adverb
alkene	Yes	No	No	No
cycloalkene	Yes	No	No	No

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

alkene: any unsaturated aliphatic hydrocarbon
cycloalkene: alkene hydrocarbon which contains a closed ring of carbon atoms, but has no aromatic character.

Other hyponyms of alkene include ethene, ethylene, cycloolefin, hexine.

alkene (noun)	cycloalkene (noun)
any unsaturated aliphatic hydrocarbon	alkene hydrocarbon which contains a closed ring of carbon atoms, but has no aromatic character.