From the verb bungle.

bungling

1. Incompetent or inept.

   Harry made a bungling attempt to catch the ball.

   • c. 1921 (date written), Karel Čapek, translated by Paul Selver, R.U.R. (Rossum's Universal Robots): A Fantastic Melodrama […], Garden City, N.Y.: Doubleday, Page & Company, published 1923, →OCLC ↗, Act 1:

     Well, he then decided to manufacture everything as in the human body. I'll show you in the museum the bungling attempt it took him ten years to produce. It was to have been a man, but it lived for three days only. Then up came young Rossum, an engineer. He was a wonderful fellow, Miss Glory. When he saw what a mess of it the old man was making, he said: "It's absurd to spend ten years making a man. If you can't make him quicker than nature, you might as well shut up shop."

bungling (plural bunglings)

1. An act of incompetence or ineptitude.

   Your bungling nearly cost us our jobs.

• Portuguese: deslize, gafe

1. Present participle and gerund of bungle