Bungle (verb)

1. To make mistakes or to act clumsily and thus spoil or ruin something.
2. To manage or carry out (a task or activity) in a clumsy or inept way.

Origin:

From the middle english word "bunglen" which means to work clumsily or to make mistakes.

Examples:

1. He bungled the job and had to start over.
2. She bungled the negotiations and lost the deal.
3. The plan was bungled from the start.
4. The company bungled the launch of the new product.
5. He bungled the interview and didn't get the job.