drink, smoke, take
飲 centers on taking something into the body through the mouth: drinking liquids, smoking, or ingesting medicine. The core idea is oral intake.
飲 combines 飠 (food/eat) and 欠 (open mouth), suggesting the act of drinking or taking in through the mouth. The modern form preserves this semantic combination clearly.
The left side 飠 relates to food and eating, and the right side 欠 looks like a person with an open mouth. Together they show someone opening their mouth to drink or take in something.
For イン, imagine drinking a refreshing inn water from a well: inn -> イン, and the open mouth 欠 drinks from the food-related 飠 source.
to drink; to swallow; to take (medicine)
drink; beverage
food and drink; eating and drinking
beverage; drink
to be able to drink
drinking alcohol
drinking (sometimes esp. alcohol); drink; drinking party
bar; saloon; pub; tavern; drinking establishment
to make (someone) drink; to force to drink; to let drink
(heavy) drinker; drunkard; tippler; boozer
to swallow; to gulp down
sampling a drink; tasting
swallowing
drinking
drinking habitually; being fond of (a drink)
soft drink
(act of) drinking water
food and drink; eating and drinking
to drink up; to drink to the last drop; to drink (a glass) dry; to drain (one's glass); to empty; to down (a drink)
heavy drinking