- Lacking common sense.
- There's no end to their daftness if they once start on that track. A lawfu' trade's a lawfu' trade, says I, and it's contrary to public policy to pit it at the mercy of wheen cranks. D'ye no agree, sir? By the way, I havena got your name? — John Buchan, ''Mr. Standfast, Chapter 8.
aberration, abnormality, alienation, brain damage, brainsickness, clouded mind, craziness, dementedness, dementia, derangement, disorientation, distraction, folie, furor, insaneness, insanity, irrationality, loss of mind, loss of reason, lunacy, madness, mania, mental deficiency, mental derangement, mental disease, mental disorder, mental disturbance, mental illness, mental instability, mental sickness, mind overthrown, mindsickness, oddness, pixilation, possession, queerness, rabidness, reasonlessness, senselessness, shattered mind, sick mind, sickness, strangeness, unbalance, unbalanced mind, unsaneness, unsound mind, unsoundness, unsoundness of mind, witlessness