Definitely not!

definitely not

Absolutely not. A: "Now, be honest—have you ever stolen money from this company?" B: "Definitely not!"
See also: definitely, not
Farlex Dictionary of Idioms.

Definitely not!

 and Certainly not!
No, without any doubt at all. (Compare this with Absolutely not!) Bill: Will you lend me some money? Bob: No way! Definitely not! Bob: Have you ever stolen anything? Fred: Certainly not!
See also: Definitely
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
See also:
  • definitely
  • definitely not
  • no doubt about it
  • absotively
  • (as) sure as hell
  • as sure as hell
  • abso
  • lutely
  • a/the pecking order
  • absotively posilutely