eyeopener

[ahy-oh-puh-ner] /ˈaɪˌoʊ pə nər/
noun
1.
an experience or disclosure that gives one a sudden realization or understanding:
Her disclosures about her childhood were a real eyeopener.
2.
a drink of liquor taken early in the day and intended to wake a person up fully.
Origin
1810-20, Americanism; eye + opener
British Dictionary definitions for eye-opener

eye-opener

noun (informal)
1.
something startling or revealing
2.
(US & Canadian) an alcoholic drink taken early in the morning
Slang definitions & phrases for eye-opener

eye-opener

noun
  1. A drink of liquor taken upon awaking: He fumbled for the jug and slurped an eye-opener (1818+)
  2. An addict's first injection of the day (1960+ Narcotics)
  3. Anything that informs or enlightens one: Listening to that story was a real eye-opener (1863+)