What is the Gothic?

How does one define Gothic? When hearing the word Gothic, I tend to think of darkness, decay and empty buildings. It turns out I'm not far off. Gothic is a word with expansive meaning. Darkness, decay, over-dramatizations and the utterly sublime are all covered by Gothic. Not to mention the culture of resistance, forbidden passion and architecture involved. I can say I'm more excited than I thought I would be for the course thus far, and I'm sure I'll learn  much more on the true meaning of Gothic.