1. Exhausted, possibly to the point of feeling disoriented. The word is related to "grog," which refers to rum that has been diluted with water. "Grog" was named after Edward Vernon, an 18th-century British admiral nicknamed "Old Grog" (because he wore a grogram cloak) who ordered that his sailors receive that mixture instead of pure rum. I can't believe I still feel so groggy after two cups of coffee. Get used to feeling groggy—that's just life with an infant.

2. slang Drunk. Do you remember last night at the bar at all? You guys were really groggy! No more shots for me, thanks. I don't want to get totally groggy tonight.