Whats an Omniual?

One of my friends (a boy) said that he was an Omniual, even though everyone says he is bi, (he has a gf), but he insisted that he wasnt, and said that he was Omni, and i know that omni means all, so unless there is more than 2 genders, isnt that the same as bi? or does it mean that he likes all kinds of crazy shite?