Luckily no one has done any work to define this at all: https://en.m.wikipedia.org/wiki/Gender_equality
And that doesn't disprove my point - I've never MET anyone who has a clear view other than mumbling about "equal numbers".
It's an interesting definition though - "the state of equal ease of access to resources and opportunities regardless of gender". This is perfectly reasonable and I don't know anyone who would disagree with it. But this won't sate the majority of so-called feminists, who want e.g. equal numbers of women on company boards. That's equality of outcome, not equality of opportunity. Equal chances to achieve don't necessarily guarantee equal achievements.