be off (one's) dot

(redirected from is off their dots)

be off (one's) dot

To be crazy or mentally unsound; to be extremely foolish or foolhardy. I'm going to go off my dot if I have to hear that blasted song once more! I think Jane's grandmother is a little off her dot these days. You must be off your dot if you think that's a good idea!
See also: dot, off