What is Graysexual?

I've recently met a man whose dating profile said that he's Graysexual. I tried Googling the term, but it's a bit confusing and I'm hoping to get a straightforward breakdown from the kind folks in this community.

From what I gather, it's a branch of asexuality that sometimes feels sexual attraction. That's a bit ambiguous, though.

I will ask the person directly once we've spoken more, but it will help to have a foundation of understanding beforehand. Thanks ahead of time!