Relou is a word you can often hear among young people: it is the verlan of lourd. Its meaning, however, is a little different: lourd means “heavy”, while relou means “annoying” or “irritating” (lourd also has this meaning, but it’s not the main one). It is used to describe a person or the behavior of this person (see also boulet).
Y a un gros relou qui essaie de draguer ma copine.
There’s a really annoying guy trying to hit on my girlfriend.
Arrête les blagues de cul, t’es lourd.
Stop telling dirty jokes, you’re annoying.
Demain j’ai cours jusqu’à dix-sept heures, c’est relou.
Tomorrow I have lessons until 5 PM, it’s frustrating.
Listen to the examples: