I accidentally deleted imovies Can I retrieve them somewhere

The term "iMovies" could be taken to refer to the independent shared out movie or to the iMovie project itself.

If you deleted a shared out movie then your recourse is to recover it from a backup like Time Machine. Failing that, you would need to use recovery software to find it.

If you accidentally deleted a project you have two options. The first option is to restore the iMovie library with Time Machine at a point in time just before the project was deleted. The second option is to retrieve the project from the iMovie Backups folder on your Mac.

To get to the iMovie Backups folder, follow this file path from the Finder menu:

Go/Home/Library/Containers/com.apple.iMovieApp/Data/Library/Caches/iMovieBackups

When you get there you will see a list of previous backups of your iMovie library.  Click on one dated just before your issue started.  iMovie will open in that library.   Navigate to your projects browser (where your projects are displayed as icons) and see if your projects are intact.

-- Rich

If you accidentally deleted the iMovie app itself, you can redownload it with this procedure:

To update/redownload iMovie 10, drag your iMovie 10 app from the Applications folder into the trash, but do not empty the trash. (You can skip that step if you had iMovie 10 on your computer before, but deleted it.) Sign in to the app store and open your purchases folder by clicking on your name at the bottom of the app store side bar.   You will see your purchases displayed, including iMovie 10. Redownload/update iMovie from there. If not successful, drag your present iMovie app out of the trash (if you moved it there) and return it to the Applications folder.

-- Rich