not hold (one's) liquor

not hold (one's) liquor

To be greatly and negatively affected by alcohol, especially becoming ill or unconscious. I'm sorry for acting like such a fool at the party—I don't even remember what happened. I guess I just can't hold my liquor. A: "Wow, Jennifer is on her fifth pint and still seems totally sober." B: "I wonder where she learned to hold her liquor like that."
See also: hold, liquor, not