Drunk is a participle like drinking, and so needs a verb after a subject. You can't say "I drunk water" any more than you can say "I drinking water". It's "I've/'d drunk water" and "I am/was drinking water" and so on. A lot of Americans I've encountered think drunk means you've had too much alcohol likely because it has a separate dictionary entry saying so. Drunk, though, is also the past participle listed under the verb drink ...
I'm getting (술)취한 for (dizzy/having trouble walking) drunk/drunken, 음주 for drunk as in drunk driving meaning having drunk alcohol (술 마셨다), 취하게 한 (like had been got drunk?) for inebriated, under-the-influence-of-alcohol gets 알코올(/술)의 영향(을 받아)?
"Drunk" is the past participle. ("I have drunk some juice.") "Drank" is the simple past. ("I drank some juice.")
The past participle is what you use to make a verb into an adjective. ("He chose poorly" vs. "He is the chosen one." Another example: "They broke the game." vs. "The game is broken.")
We don't think about it because lots of times the past participle and simple past form of a verb are identical. Above, I used examples that aren't, but: "I finished my homework" vs. "I have finished my homework" vs. "Finished assignments should be handed in tomorrow." "Finished" looks identical in both cases but isn't.