much like "for real", showing you are serious about something with a little less seriousness.

Anatidaephobia is defined as a pervasive, irrational fear that one is being watched by a duck. The anatidaephobic individual fears that no matter where they are or what they are doing, a duck watches.

Anatidaephobia is derived from the Greek word "anatidae", meaning ducks, geese or swans and "phobos" meaning fear.

the word 'for sure'
but for cool kids

you understand something and you like it

Short form of the jive word "foshizzle," or white colloquialism "forshizzle," which both mean "for sure."