half under
slang Drunk, mildly drunk, or nearly drunk. Sorry I didn't call you last night—I had some wine, got half under, and fell asleep.
half-under
1. Partially unconscious, typically in reference to the effects of anesthesia. (The word "under" is commonly used to indicate that someone has been rendered unconscious by anesthesia.) I'm terrified that I'll only be half-under and will feel everything the surgeon is doing.
2. slang Drunk, mildly drunk, or nearly drunk. Sorry I didn't call you last night—I had some wine, got half-under, and fell asleep.