The googled term of omnisexual is "People who identify as omnisexual are attracted to those of all gender identities and sexual orientations. Omnisexuality is in the category of multisexuality, which includes people who are attracted to more than one gender."
The way that I would like to explain an omnisexual person to someone is that it is a sexuality under the bisexual umbrella. This means that you would of course like more than one gender (as the google definition states) This sexuality is also very similar to another sexuality called pansexual. A pansexual is a person who is gender-blind meaning that they like the person for merely for their personality. To sum it up in some simple words, they like someone just for their personality. Not for their gender, or sexuality. Similar to pansexuals, omnisexual people like people no matter the sexuality. Likewise, they are not gender-blind and usually have a preference. Now that you understand the meaning you can now return to the home page!