cowboy

Characterised by reckless, irresponsible, or unprofessional behaviour, often in business.

"They were accused of cowboy tactics in their business dealings."

A person, often American, who herds and tends cattle on a ranch.

"The cowboy rode his horse across the plains."

An unskilled or dishonest worker, especially in a trade, doing poor quality work.

"Don't hire that cowboy builder; he'll botch the job."