The majority opinion is the OSI definition and approved licenses but not everyone agrees.

source is open as "open to read, download, and run" (and even modify as soon as you're doing it privately)?

If you can't change it and distribute your changes it's no longer open; pretty much by definition.

Maybe you're thinking of "looky loo" software or something? But if you can't change it and if you're not allowed to share your changes then it is NOT open.