This is basically a Japanese internet slang used commonly to define people who are obsessed with the Japanese culture.

Some people see them as annoying, since they always like to imitate the Japanese culture, even if they're not Japanese.

Someones who's life only resolves on anime, manga and video games. They wear products that resolves to an anime or video game and only talk about it. It gets annoying.

Someone who's world revolves around anime and manga and that's all they freakin' talk about 24/7 because they don't know anything about anything else in the world. They are like otaku's but worse and and major geeks and nerds. AKA Melissa Leonard. They also bash the japanese culture and language by trying to talk japanese and saying KONICHIWA!!! OMG THAT'S KAWAII DESU!!! NYA!

An insult used towards people who watch anime, use a few Japanese words in normal sentences (Most of the time learned from anime.), thinks that everyone's opinion is irrelevant compared to their own, and want to move to Japan based on what they've seen from anime. Not to be confused with an otaku, a weaboo is completely different. Sometimes weeb is also said, which is a synonym to weaboo.

A misspelling of the word 'weeaboo'

someone who likes anime a lot but denies it even though he asks other to play anime games with him