I was mostly going down a sciencey path, but "real" is a fairly well understood word (part of reality; not imaginary).

In terms of philosophy I'm mostly of an empirical bent. Things which are observable are real, and things which aren't observable directly, but have a observable effect that can be repeatedly demonstrated on demand, are real too (though they may not be exactly as hypothesised if all we can see are their effects). This is how electromagnetism and quantum tunnelling can be real at the same time faeries aren't.