In colloquial speech, this refers to an absurdity or a piece of nonsense. It is used when someone says something completely incoherent or makes a blunder during a conversation.
We were talking about politics and your sister-in-law dropped such a huge roca about religion.
An expression used when something is completely absurd, ridiculous, or shocking. It implies that a person or situation is an absolute joke or a total embarrassment.
La burla with those clothes. I cannot believe you said that, you are la burla.
To become a FARUCA refers to someone who loses their self-control for some reason and goes a bit wild, or rather, totally off the rails. (This usage is regional).
In the memoir I Confess That I Have Lived, Pablo Neruda explains that Federico Garcia Lorca used this word to describe funny and nonsensical objects or situations (Garcia Lorca was a famous Spanish poet and Neruda was a Chilean Nobel laureate).
Garcia Lorca says to Neruda about a dog they find: Pablo, I bet this dog is very chorpatelico. Neruda asks him: What is chorpatelico? Garcia Lorca replies: I have no idea, but you have to admit it is very chorpatelico.