one who has no sexual orentation. sex is not important
"did you see that girl she's so hot!" "didn't anyone tell you, she's a nonsexual."
A person who, even after a prolonged period of observation, does not present one with a clear indication of whether they are male or female.
Guy 1: "Hey, see that person over there? It's too ugly to be a woman but it's wearing a floral shirt and platform shoes. Is it a guy?"
Guy 2: "And I can't tell if it's got breasts or not. The odd hairstyle doesn't help. I can't stand it when you can't tell if someone is a guy or a girl. We'll just have to classify that as a 'nonsexual'. Poor ugly bastard."