So which is it - freak out or piss off? Or does it mean both.

Uly, I think it's both. It means Это бесит, выводит меня из себя.

What does freak out mean to you?

"бесить, раздражать". Неправильно?

Not quite, it means that you heard or saw something that gave you a very creepy feeling. I don't know if it's correct, but my guess in Russian would be мне стало невероятно жутко.

I don't know. Judging by what's said here, these both phrases fit for this translation:
http://www.nashaamerica.com/blogi/education/item-5213/
What do you think? Or the Russian translation is incorrect?

Elena, the person who wrote that has no idea what FREAK OUT means. It's not about anger, it's more about astonishment and disbelief about something so unexpected, or unbelievable, or sudden that your mind doesn't have time to process it. For instance, in the scene from The Hangover - there are too many things happening at once and the character can't process them all - one guys missing a tooth, there's a tiger in the bathroom, the other guy is freaking out about the tiger, etc. In the scene with the rattlesnake, the is creeped out by the fact that the dead snake is still moving - his mind can't process it. Excuse the expression, but it's closer to в полном аху*е.

The confusion comes from the fact that FREAKING OUT in the progressive, is different from FREAK OUT, which means психнуть, to get really angry about something. "When I told him I wrecked his car, he freaked out." (he go really angry and started screaming, etc.)

So if, for example, you watch a movie about the end of the world and for days you can't stop thinking about it, and having nightmares, etc., you can say "That movie freaked me out" - it gave you a creepy feeling, you can't stop thinking about it, you found it ominous and scary.

He freaked out = 😤😖 He was freaking out, something freaked him out = 😳😱

Oh, I wouldn't guess the meanings are different in the simple and the progressive. so, something freaked him out - что-то навело на него страх и ужас?

That's correct, except it doesn't have to be strax and uzhas, it could just be something that you found creepy and couldn't stop thinking about. The other day, my neighbor and I were taking a walk and we ran into a friend of ours who just had a baby. The baby's skin is café au lait, but her eyes are a crystalline light blue that's almost white. When we walked away, my friend say "Cute baby, but those eyes freaked me out." In other words, he found them creepy.

бросающий в дрожь, вызывающий страх?

I guess, I don't really know what those things mean. It's more about shock, and less about fear.

"Быть в шоке, потерять самообладание" - наверное, так.
Спасибо большое за разъяснение! You can already make a dictionary out of your explanations. It'll be called "Толковый словарь английского языка Ули Марреро" :-)

hahahaha it'll be a bestseller! The first want to buy it will be Aleh)

No, Aleh already disappeared from our view. He obeyed the mysterious German and "stopped breathing". The first will be me :))

Your copy is on the house!

Wow, with the autograph!

An autographed copy!

Deal! (Замётано)

👍🏼

In the meantime, check this out: https://lingvolive.com/posts/951535

Alrighty). And can you have a look at this: https://www.lingvolive.com/en-us/community/posts/951270

Спасибо вам!!

Done!