What does [disuru] mean?
[Disuru] is the Japanese slang/verb, which means 「make a fool of a person、abuse somebody severely, criticizing, insulting」, and used among young people. Sometime it is written as 「disる」
Originally it came from English. Dis (ディス) means an opposite of some words. So example 「like v dislike」. It has been said that this [disる], which quite often used by young people, came form 「disrespect」. Disrespect is a noun which means [lack of respect or courtesy] and as a verb means [ show a lack of respect for, insult]. Insulting [侮辱する・ぶじょくする」is much similar meaning for disる. The Japanese took only [dis] , added ru (る）to it and started using as a verb. At first 「disる」 was used over the internet /SNS as a meaning of disrespect after 2000. Later on, it has been changed its meaning as scornful, despise, and finally it has stayed.
The use 「ディスる」as a simple tense and 「ディスられる」as a passive tense.
When to use it?
We use for the situation where we criticize someone/something, make a fool of someone. It is a negative word, therefore it is needed to be careful when we use it.
Ano ko wa K-POP ga daisuki de, J-POP no koto wa yoku disru yone.
That girl love K-POP and often criticize about J-POP.
Youtube no doga ni tuite, takusann no hito ga disru komento o kaite iru.
Many people are writing insulting comments on a youtube video.
Itsumo niko niko shite shigot shiteiru noni, kage dewa hito wo disste iru.
Always working with a smile, but taking behind someone’s back.
Kiteiru mono o tomodachi ni disurareta.
I was insulted by a friend because of what I was wearing.
Hope it is informative and interesting to you.