highball vs mixed drink

highball and mixed drink both are nouns.

Word	Noun	Adjective	Verb	Adverb
highball	Yes	No	No	No
mixed drink	Yes	No	No	No

As nouns, mixed drink is a hypernym of highball; that is, mixed drink is a word with a broader meaning than highball:

highball: a mixed drink made of alcoholic liquor mixed with water or a carbonated beverage and served in a tall glass
mixed drink: made of two or more ingredients

highball (noun)	mixed drink (noun)
a mixed drink made of alcoholic liquor mixed with water or a carbonated beverage and served in a tall glass	made of two or more ingredients