ain't got a grain of sense

ain't got a grain of sense

Is very foolish or lacking common sense. Jimmy almost crossed the street without looking up from his cell phone. He ain't got a grain of sense!
See also: grain, of, sense

ain't got a grain of sense

 and ain't got a lick of sense
Rur. is or are foolish. Mary spends money like there's no tomorrow. She sure ain't got a grain of sense. I wouldn't trust Jim to take care of my kids. He ain't got a lick of sense.
See also: grain, of, sense