Cool!

One of the most overused slang terms in every day conversation is “cool”. It’s a word referring to something awesome, stylish, and nice among other things. You may use it when you're not really listening to someone and or you don't have enough knowledge of the subject matter, yet you want to participate in the conversation.
There is an image of a smiley face wearing sunglasses, meaning that something is so cool and one can use it in chat, e-mail, etc.

Here is a sample of a cool smiley icon:

I am so cool!

In Farsi language, the equivalent word of “cool” is “ایول” which is pronounced as /eyval/.
How do you say “Cool” in your language?