brain fog

[ breyn-fog, fawg ]

  1. a mental state marked by difficulty remembering, concentrating, or thinking clearly, often caused by exhaustion, stress, or illness: He had so much brain fog that a single thought felt impossible.For new parents, fatigue and brain fog seem inevitable.Research has found that long COVID can cause brain fog and memory loss.

Origin of brain fog

First recorded in 1850–55; brain + fog1
  • Also brain-fog, brain·fog .

Words Nearby brain fog Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023