That's how a language grows. Old words die - or take on a new life. New words appear. Language wordstock is replenished, refreshed, and the language remains vibrant and serviceable, ready to describe new concepts, ideas, and objects. Many language purists object to this way of growth. But we have to remember that just as yesterday's liberal is often tomorrow's conservative, in many cases, what was considered slang in the past, eventually acquires respectability.

As quoted in Dickson, Paul (2014), Authorisms: Words Wrought by Writers