that dog won't hunt

old-fashioned Primarily heard in US.

1. That claim, argument, or explanation is inaccurate or unfounded. My opponent claims that my administration has hurt the economy, but you only have to glance at the statistics to know that dog won't hunt. A: "Our company could have really been successful if you hadn't held us back like that!" B: "Come off it, Jack, that dog won't hunt. I've done all I could to make this company a success, and you know it."

2. That idea or proposal is not viable or has no chance of succeeding; that won't work. A: "Why don't we try lowering the price?" B: "Nah, that dog won't hunt. We need something that grabs people's attention, not just a cheaper product." Tom wants to sue them, but that dog won't hunt if you ask me. They've got enough money to hire the best legal team in the country.

that dog won't hunt

This idea or excuse won’t work. This folksy expression originated in the American South, where dogs are commonly used to hunt raccoons and other wild animals. Also put as that old dog won’t hunt, it originated in the late 1800s.