- The definition of groggy is a state of being out-of-it or dazed due to being sick or tired.
If you've just gotten off of a 10-hour plane trip and you've been awake all night, this is an example of when you would be described as groggy.
A groggy traveler.
Origin of groggyFrom grog.
(comparative groggier, superlative groggiest)