I suppose not

I suppose not

An expression of vague denial or negation. A: "Is Tom coming?" B: "I suppose not—it's getting pretty late."
See also: not, suppose
Farlex Dictionary of Idioms.
See also:
  • I guess so
  • suspect
  • vague
  • I guess
  • aint
  • ain't
  • by no means
  • aren
  • definitely
  • Definitely not!