I'd agree for "shell", "terminal", "console", something like that. But to me, the distinction is whether or not it has a text interface. That is, I interact via text, and it responds in kind.

What about a GUI program that uses text to control it? Many GUI programs do have command-line components in them (editors, ides). (not suggesting that makes them command line programs per se, but that the idea of "command-line"-ness transcends X)