alkyl group vs methyl

alkyl group and methyl both are nouns.

Word	Noun	Adjective	Verb	Adverb
alkyl group	Yes	No	No	No
methyl	Yes	No	No	No

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

alkyl group: any of a series of univalent groups of the general formula CnH2n+1 derived from aliphatic hydrocarbons
methyl: the univalent radical CH3- derived from methane

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

alkyl group (noun)	methyl (noun)
any of a series of univalent groups of the general formula CnH2n+1 derived from aliphatic hydrocarbons	the univalent radical CH3- derived from methane