How do you say random?
In this context: like when you're talking about one thing, and someone pops up with something completely different. We say, "wow, that was random." How do you communicate this? I have been told "raro," but is there something else?
Or like "This chick randomly came up to me and accused me of....and I've never even met her!" etc. (example only, haha)
Again, I am looking for that colloquial context, like how teenagers talk. I once saw "al azar," but a friend told me he doesn't think that's right.
You can also say "de la nada".
Esa chica salió de la nada y me...
Throw some coins up in the air and note how they land; roll a couple of dice and see what you come up with. Your results are sure to be random, that is to say due entirely to chance.
The idiomatic use which you are describing is more along the lines of "unexpected," "sudden and unexpected," "out of left field," "out of nowhere," or "out of the blue."
Aside from what others have already said (in particular LuisaGomez), I suppose that in certain contexts you might be able to get away with "imprevisto" or "de súbito."
This chick randomly came up to me and accused me of....
Esta chava me enfrentó de súbito/de manera imprevista y me acusó de...
wow, that was random
¡Hala! eso fue imprevisto!
Still, I think that Luisa has probably come up with the closest approximation to the expression you are looking for.
inesperado = Unexpected, unforeseen.
Hola Random is whyatdbddf namely,irrelavent
Esta chica al azar/impensadamente se me acercó y me acusó de ....
azar =good for "random" in your context as in "by chance"
or you could go for "suddenly" de repente
por casualidad, = by chance.