pomatum vs hair oil

pomatum and hair oil both are nouns.

Word	Noun	Adjective	Verb	Adverb
pomatum	Yes	No	No	No
hair oil	Yes	No	No	No

As nouns, hair oil is a hypernym of pomatum; that is, hair oil is a word with a broader meaning than pomatum:

Other hypernyms of pomatum include hair grease, hair tonic, hairdressing.

pomatum (noun)	hair oil (noun)
hairdressing consisting of a perfumed oil or ointment	a toiletry for the hair