not set the Thames on fire

To do wonderful or exciting things; to cause a great or remarkable sensation in the world; to be extremely exciting, popular, famous, renowned, etc. (Refers to the Thames river in London. Often used in the negative to indicate the opposite.) Primarily heard in UK. I wouldn't be too concerned with what he thinks of you. For all his money and education, he's hardly setting the Thames on fire, is he? When she was a child, Janet dreamed of setting the Thames on fire as a famous actress.

If you say that someone or something won't set the Thames on fire, you mean that they are not very exciting and are not likely to be extremely successful. None of these dishes would set the Thames on fire, but they were well prepared and good value for money. Note: You can replace Thames with the name of another river. They both had fairly successful careers in North America, without exactly setting the Hudson River on fire.