alkyl vs ethyl radical

alkyl and ethyl radical both are nouns.

Word	Noun	Adjective	Verb	Adverb
alkyl	Yes	No	No	No
ethyl radical	Yes	No	No	No

As nouns, ethyl radical is a hyponym of alkyl; that is, ethyl radical is a word with a more specific, narrower meaning than alkyl:

alkyl: any of a series of univalent groups of the general formula CnH2n+1 derived from aliphatic hydrocarbons
ethyl radical: the univalent hydrocarbon radical C2H5 derived from ethane by the removal of one hydrogen atom

Other hyponyms of alkyl include ethyl, ethyl group, methyl, methyl group, methyl radical.

alkyl (noun)	ethyl radical (noun)
any of a series of univalent groups of the general formula CnH2n+1 derived from aliphatic hydrocarbons	the univalent hydrocarbon radical C2H5 derived from ethane by the removal of one hydrogen atom