malted milk vs milkshake

malted milk and milkshake both are nouns.

Word	Noun	Adjective	Verb	Adverb
malted milk	Yes	No	No	No
milkshake	Yes	No	No	No

As nouns, milkshake is a hypernym of malted milk; that is, milkshake is a word with a broader meaning than malted milk:

malted milk: a milkshake made with malt powder
milkshake: frothy drink of milk and flavoring and sometimes fruit or ice cream

Other hypernyms of malted milk include milk shake, shake.

malted milk (noun)	milkshake (noun)
powder made of dried milk and malted cereals	frothy drink of milk and flavoring and sometimes fruit or ice cream
a milkshake made with malt powder