make nonsense of

make (a) nonsense of (something)

To treat something serious or important in a silly or ridiculous manner; to make a mockery of something. The candidate has been making a nonsense of the whole political process, but for some reason many voters feel that that is just what's needed. I don't appreciate you making nonsense of this class with your rude remarks and obnoxious behavior.
See also: make, nonsense, of
Farlex Dictionary of Idioms.

make nonsense of something

to make something appear to be silly or nonsensical. You are just making nonsense of everything I have tried to do. Your statement makes nonsense of everything you have said before.
See also: make, nonsense, of
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.

make nonsense (or a nonsense) of

reduce the value of something to a ridiculous degree.
See also: make, nonsense, of
Farlex Partner Idioms Dictionary
See also:
  • a straw will show which way the wind blows
  • a/the feel of (something)
  • (I) wouldn't (do something) if I were you
  • a crack at (someone or something)
  • all right
  • (you) wanna make something of it?
  • all for the best
  • a thing of the past
  • a slew of (something)
  • a bird in hand