The word slang and informal go hand in hand as it the use of an informal way of communicating in certain groups. This was usually done in order to establish group identity or exclude outsiders but as of now, it is being widely used by all. One new slang today will spread like fire by tomorrow.
It is very difficult to find out about the time when such words, phrases came into existence because slang is more of a speech than being a written language. We will now find it in dictionaries too. It is also being used over the Internet worldwide. Eric Partridge was the first one to come up with his views regrading the emergence and use of this language. The development of slang is mostly considered to be lovely and creative speech process.
There are some slangs which are created by joining two different words and making into a new and trendy word with a different meaning. Such type of slang is called portmanteau slang. Some famous examples are:
This is a combination of the words brother and romance which when combined means an intense friendship between two men.
This is combined using the words friend and enemy which means a friend who is a little bit of both.
It is a combination of chill and relax which means calm down.
It is the combination of crazy and drunk which means not under control after having alcohol.
It is a combination of man and purse which simply means man's purse. Well, this one was not needed at all.
It is the combination of situation and comedy which means a situational comedy.
These were the most common examples of this type of slang, but the counting does not end here. You can find a really long list of such words.
Examples of modern and most common slangs:
Well, this is the most trending one among the youths. It stands for "before anyone else." It is used among partners or very close friends.
This acronym stands for "greatest of all time". It is mostly used in case of compliments.
This stands for "joy of missing out" and "fear of missing out".
This is a combination of stalker and fan. It means devotees of any celebs.
One time password, no here it's different. It means "one true pairing" with reference to couples.
It is used for one who is well aware of current affairs.
It is used when something so crazy happens that your wig may fall off. No matter you are wearing a wig or not. It is more like ROFL.
So here was a list of some trending slangs, be sure to keep yourself updated with them otherwise you will be termed as "old school".