brain fog

[ breyn fog, fawg ]

noun

1. a mental state marked by difficulty remembering, concentrating, or thinking clearly, often caused by exhaustion, stress, or illness: For new parents, fatigue and brain fog seem inevitable.

   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.

Word History and Origins

Origin of brain fog¹

First recorded in 1850–55; brain ( def ) + fog ¹( def )