We use the term "project manager" a lot. Of course, this role simply refers to the person that manages a project. You may not have the title of a formal project manager in your organization, but the project manager is the role of the person managing the project.
Defining scope is perhaps the most important part of the initial definition and planning process. If you don’t know what you are delivering and what the boundaries of the project are, you have no chance for success. If you have not done a good job of defining scope, managing scope will be almost impossible.