This means that someone or something is slow or r*tarded. Just like Nicki Minaj fans of course. This is not my word I got it from the Clitbeaters on ig.
A Rebar is a term used to describe pedophiles and/or lolicons that reside in low quality anime servers such as KissCommunity. It is commonly known as a derogatory and humiliating term to describe someone that defends themselves too much regarding their tendencies towards sexualizing children.