This is not about this site's scope. I'm asking this because two questions a week apart seemed to share the same misconception about what "fantasy" was, seeming to take the general sense of the word rather than as a name of a fiction genre. They were both closed relatively quickly.
This is one of them: Girl from poor background adopted by lord, falls for her half-sibling?
(Although OP was referring to a work of literature, I got the sense that it was more a 19th century gothic romance novel than anything with wizards or swords.)
The relevant help center topic appears to assume that people know what "science fiction" and "fantasy" are. It's hard to confuse "Science fiction" with anything else, but "fantasy" might be a tougher concept for non-native English speakers.
The definition might only need to be minimal. As my comment asked OP,
Cutting to the chase here, are there any magical or supernatural elements to the story?
Update: Well I just saw the following comment in this recent question:
I think that the difference of opinion here is that we have different angles towards what "fantasy" is. I am using fantasy as in "I have a fantasy about driving my car over a cliff". Whereas everyone else is using fantasy as a genre. -athornton
This gets to the heart of the matter: Can we at least agree (and document) that "fantasy" refers to the fiction genre?"