IPA: /ˈdrɪŋkər/
KK: /ˈdrɪŋkər/
A person who consumes liquids, especially alcoholic drinks, often in large amounts or regularly.
He is known as a heavy drinker at parties.
Drinker → It is formed from "drink" (from Old English *drincan*, meaning to consume liquid) and "-er" (meaning a person who). A drinker is a person who consumes liquid, typically referring to someone who drinks alcoholic beverages.
Think of someone who 'consumes liquid' ('drink') — the '-er' just means a person. A drinker is someone who drinks.