expression
I can't help but laugh; this is too funny
Internet slang used when something is so funny that laughter is unavoidable. Often seen in online comments and social media.
See also: 草
この動画、草不可避ｗ
This video is too funny, I can't stop laughing lol.
あのコメント見た？草不可避だったわ。
Did you see that comment? I couldn't help but laugh.
草 is the core slang term for laughter (like 'lol'), while 草不可避 is a set phrase meaning the laughter is unstoppable.
Derived from internet slang 草 (kusa, 'grass'), which represents laughter (from the shape of 'w' for 'warai'). 不可避 (fukahi, 'unavoidable') is added to mean 'unavoidable laughter'.