Often mistaken for stories related to homosexual men the true meaning is usually set aside for the ignorant foreigners who generalized the meaning with out clearly thinking through (mostly Fat white Americans)
Yaoi considered to be the women's equivalent of the men's adapted erotic fiction. There are no sections identified as the Yaoi genre at the Comic Market but the books are there nevertheless (hidden within the adaptations and parodies genre and the fan club genre). Yaoi was originally an abbreviation for a self-mocking statement regarding erotic adaptations regardless of the gender of the creator. (Ya-O-I = "Yama nashi, Ochi nashi, Imi nashi" which means "No build up (in storytelling), no wrapping up (the conclusion), no real deep meaning (in doing the book)".) For whatever reason, the term now has attached itself with erotic adaptations and parodies created by women. The material that would be classified into this genre primarily involves gay relationships between the handsome or cute (male) characters. The genre tends to overlap with the adaptations and parodies genre, but this is not always the rule, for there is considerable crossover with the "June" category, as well as the fan club genres.
(borrowed from http://www.tc.umn.edu/~kane0034/doujin/jargon.htm )

Yaoi is a slang meaning 'boys love' or homosexuality that is used in the japanese language. Popular with fangirls who like their favorite anime guys to kiss.

Yaoi is a Japanese word, which is actually something of an acronym. It comes from "YAma nashi, Ochi nashi, Imi nashi", which means "no climax, no point, no meaning".

In speech and writing, it's a slang term used to refer to stories that focus on homosexual relationships, usually between men. Yaoi tends to involve graphic sex, often with little or no plot. The female equivalent is yuri.

A related genre is shonen-ai, or "boys' love", which tends to involve less sex and more cuddling (and plot).

Gay poooooooooooooorn. ;D

EVERYONE KNOWS it stands for Young Academics On Ice!! Gawd.

(at least, that's what you tell your parents... muahahaha...)

Anime, manga, or fanfic that depicts explicit relationships between two males. Usually focuses on the passionate/ lustful/ physical side of the relationship, unlike shounen-ai which focuses on the romantic/ loving/ emotional side. Usually R rated or higher.

1. Y-A-ma nashi O-chi nashi I-mi nashi - translated: no climax, no point, no meaning.

2. Yamete! Atashi no Oshiri Itai! translated: Stop it! My butt hurts!

A type of anime that involves gay male pairings. AKA BUTTSECKS!! Boy love.
There's different levels of yaoi. Some are light (shonen-ai) and some are pretty bad. It can be anywhere in between, too.