oil of anise vs essential oil

oil of anise and essential oil both are nouns.

Word	Noun	Adjective	Verb	Adverb
oil of anise	Yes	No	No	No
essential oil	Yes	No	No	No

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

oil of anise: an essential oil extracted from the seeds of Pimpinella anisum (aniseed), having a pungent liquorice-like smell.
essential oil: an oil having the odor or flavor of the plant from which it comes; used in perfume and flavorings

Other hypernyms of oil of anise include volatile oil.

oil of anise (noun)	essential oil (noun)
an essential oil extracted from the seeds of Pimpinella anisum (aniseed), having a pungent liquorice-like smell.	an oil having the odor or flavor of the plant from which it comes; used in perfume and flavorings