wintergreen oil vs flavouring

wintergreen oil and flavouring both are nouns.

Word	Noun	Adjective	Verb	Adverb
wintergreen oil	Yes	No	No	No
flavouring	Yes	No	No	No

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

wintergreen oil: oil or flavoring obtained from the creeping wintergreen or teaberry plant
flavouring: something added to food primarily for the savor it imparts

Other hypernyms of wintergreen oil include flavorer, flavoring, flavourer, seasoner, seasoning.

wintergreen oil (noun)	flavouring (noun)
oil or flavoring obtained from the creeping wintergreen or teaberry plant	something added to food primarily for the savor it imparts