The phrase "imprecise language" means using words or phrases that are not clear or specific enough, making it difficult to understand or communicate accurately. Full definition
I apologize for using imprecise language there. (slate.com)
The end of the world is no excuse for imprecise language, at least not for the four couples at the center of «It's a Disaster,» whose vegan - friendly brunch is interrupted by the detonation of some dirty bombs a few miles away. (backstage.com)
Perhaps I used imprecise language saying an axiom is a definition, I meant axioms are defined, mathematicians define them. (religion.blogs.cnn.com)