ingestion vs drinking

ingestion and drinking both are nouns.

Word	Noun	Adjective	Verb	Adverb
ingestion	Yes	No	No	No
drinking	Yes	No	No	No

As nouns, drinking is a hyponym of ingestion; that is, drinking is a word with a more specific, narrower meaning than ingestion:

ingestion: the process of taking food into the body through the mouth (as by eating)
drinking: the act of consuming liquids

Other hyponyms of ingestion include eating, feeding, deglutition, drink, swallow, suck, sucking, suction, imbibing, imbibition.

ingestion (noun)	drinking (noun)
the process of taking food into the body through the mouth (as by eating)	the act of consuming liquids
	the act of drinking alcoholic beverages to excess