Everybody loves to chill out but what does it mean? It simply means to relax. Usually it can be used with or without the word ‘out’ and if you’re speaking with an American English speaker they’ll definitely understand.

Example 1)

“Hey Tommy, what are you guys doing?”

“We’re just chilling (out). Do you want to come round?”

Example 2)

“Sue, what did you do in the weekend?”

“Nothing much. We just chilled (out).”

But if someone tells you need to chill out it’s not as positive. It means that they think you’re overreacting to a situation or getting stressed about silly little things.      

Example 3)

“I can’t believe that test we just had. I’m sure I’m going to fail.”

“You need to chill out and stop thinking too much. I’m sure you’ll be fine.”