aniseed oil vs oil of anise

aniseed oil and oil of anise both are nouns.

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

As nouns, aniseed oil and oil of anise are synonyms defined as:

aniseed oil and oil of anise: an essential oil extracted from the seeds of Pimpinella anisum (aniseed), having a pungent liquorice-like smell.

Other synonyms of aniseed oil include anise oil.

aniseed oil (noun)	oil of anise (noun)
an essential oil extracted from the seeds of Pimpinella anisum (aniseed), having a pungent liquorice-like smell.	an essential oil extracted from the seeds of Pimpinella anisum (aniseed), having a pungent liquorice-like smell.