drink
飮 centers on the act of drinking, specifically taking liquid into the mouth.
飮 is the older form of 飲, combining the food radical ⻞ with 欠 (open mouth), suggesting drinking or consuming liquid. The modern simplified form 飲 replaces the left component with 食.
The left side ⻞ represents food or eating, and the right side 欠 looks like a person with an open mouth. Together they show someone opening their mouth to drink.
For イン, imagine drinking an inn's special brew: inn -> イン, and you open your mouth to drink it.