The term is thrown around a lot, so I’m going to define it clearly:

So to elaborate on that definition…a trope becomes a cliché if it’s frequently repeated and poorly implemented. This is an and situation and not an or situation.
Why is it important that both of these conditions be satisfied? Well, because what a trope is is any re-occurring element in stories. This includes everything from ‘grizzled veteran with a beard’ to ‘woman’…or even ‘chair’. Notice that the presence of a woman doesn’t make a story automatically bad. Well…I guess that’s debatable.
Anyway…a cliché is what happens when a writer copies a trope from somewhere else, but doesn’t consider the context within which that trope actually existed.