be off (one's) dot(redirected from be 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!
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.