Ah, well, yes, the C-word is pre-scientific term and those are always hard to deal with. But I think "understanding natural language" is one of the easier ones, at least inasmuch as we can resort to referring to the intentions of the speaker, and understanding being the congruence between that and the hearer's impression of it. And it just seems like a category error to say that any natural language processing system has anything like that, since the thing doing the understanding is so radically different to the one doing the speaking.