In The Drink Meaning

(idiomatic, possibly dated) Under the influence of an intoxicating beverage.

Example: 1907, Samuel Hopkins Adams, and Stewart Edward White, The Mystery, ch. 8:
  "I'm broke. I came down here wondering whether I'd better throw myself in the drink."
1920, Peter B. Kyne, Kindred of the Dust, ch. 44:
  "I've been in the drink," and he related the tale of his recent adventures. "Your raftsman saved my life."
2010 May 24, Peter Ha, "Point, Click, Drop and Dive," Time:
  When it comes to cameras, the only thing worse than dropping one on the ground is dropping one in the drink.
1892, W. H. Hudson, Fan: The Story of a Young Girl's Life, ch. 1:
  [H]e ain't so bad neither, when he's not in the drink. He's sorry he hit me now."
c. 1893, Frances Hodgson Burnett, "Little Saint Elizabeth":
  "It's no place for the loike o' yez," she said. "An' it black noight, an' men and women wild in the drink; an' Pat Harrigan insoide bloind an' mad in liquor."
1896, George MacDonald, Salted With Fire, ch. 12:
  "I cannot tell what I may have done in the drink. I may even have told his name, though I remember nothing about it!"