Yaoi is a term used to describe adult themes and graphic materials centering on romantic relationships between two (or more) males (always NC-17+ rated). Yaoi is actually a Japanese acronym shown below.

YAma nashi (Without climax)
Ochi nashi (Without conclusion)
Imi nashi (Without content)

Yaoi is basically a PWP. Like the components that make up its name, yaoi does not have a point, meaning, or end (seemingly), seeing as it is, most often, just graphic sex, and, in no ways limited in explicit descriptions of foreplay.

Some can argue that yaoi is not meaningless. However, yaoi is often utilized in shounen-ai pieces, which concentrate on the plot. Yaoi, itself, is the detailed description of the sexual process, which can be easily left out of the piece without changing the depth of the story. Still, it is according to preference whether one would want to read/see a simple lime or a full-blown lemon. Of course, there are people who favor plain shounen-ai.

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.