half a bubble off plumb

half a bubble off plumb

Strange; silly; crazy. Referring to the bubble inside a level. A: "She's a sweet old lady, but yeah, she's definitely half a bubble off plumb." B: "OK, yeah, I was sort of startled when she started talking to her rosebush."
See also: bubble, half, off, plumb
Farlex Dictionary of Idioms.

half a bubble off plumb

Fig. giddy; crazy. She is acting about half a bubble off plumb. What is wrong with her? Tom is just half a bubble off plumb, but he is all heart.
See also: bubble, half, off, plumb
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.

half a bubble off plumb

phr. giddy; crazy. Tom is just half a bubble off plumb, but he is all heart.
See also: bubble, half, off, plumb
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions
See also:
  • plumb
  • athlete
  • be a (something) in the making
  • crisis
  • come out on top
  • be dragging (one's) feet
  • be dragging your feet
  • as the case may be
  • not be much of a something
  • be not much of a (something)