We Need to Agree On a Set of Rules For Calling Something a Lie

CBS News today uses an increasingly common description of a Trump falsehood:

Barton Gellman is not impressed:

So here’s a good question: If someone says something with no evidence, is it a lie? Please don’t try to evade the question with a knowing reference to On Bullshit, either. Let’s assume—because I’m a charitable guy—that Trump isn’t affirmatively aware that there are no terrorist attacks that the media has ignored, and is deliberately saying the opposite. Let’s assume, instead, that he just doesn’t know, and said it because it sounded good.

Is that a lie?