Czenglish: My husband is a really good writer. He has a great fantasy.
English: Oh, that sounds a bit x-rated…
Czenglish: What? I just mean he is very creative!
English: Haha, I guessed that – you should have said ‘he has a great imagination’.
Fantasy is innocently used when related to dreams. It is also used as a movie genre – so for example, Lord of The Rings is a fantasy series.
Beyond that be careful to use this word how you actually want to use it, as it often carries a sexual connotation.