heptane vs methane series

heptane and methane series both are nouns.

Word	Noun	Adjective	Verb	Adverb
heptane	Yes	No	No	No
methane series	Yes	No	No	No

As nouns, methane series is a hypernym of heptane; that is, methane series is a word with a broader meaning than heptane:

heptane: a colorless volatile highly flammable liquid obtained from petroleum and used as an anesthetic or a solvent or in determining octane ratings
methane series: a series of non-aromatic saturated hydrocarbons with the general formula CnH(2n+2)

Other hypernyms of heptane include alkane, alkane series, paraffin, paraffin series.

heptane (noun)	methane series (noun)
a colorless volatile highly flammable liquid obtained from petroleum and used as an anesthetic or a solvent or in determining octane ratings	a series of non-aromatic saturated hydrocarbons with the general formula CnH(2n+2)