Completely exhausted of ideas, patience, or solutions; unable to think of what to do next in a difficult situation.
Dating to the 14th century, this phrase originally referred to reaching the end of one's mental resources or intelligence ('wit' meaning knowledge or mental capacity). The expression appears in Chaucer and reflects the medieval understanding of wit as a finite resource that could be depleted through overuse or stress.
The phrase perfectly captures the feeling of mental exhaustion that we now understand as cognitive overload. Medieval people conceived of intelligence and problem-solving ability as having literal boundaries - once you reached your 'wit's end,' you'd used up all your mental capacity, which aligns surprisingly well with modern understanding of decision fatigue.
Complete word intelligence in one call. Free tier — 50 lookups/day.