If you’ve been around teenagers lately, you’ve probably noticed their unconventional uses of certain words or phrases. For example, “tea” now means gossip (as in, “Spill the tea!”), “bet” is now used as a way of saying “yes,” and if something “slaps,” it means that it’s a good thing (as in, “that movie slaps!”).

As strange as it may seem, drastic changes in the way words are used is no new phenomenon.

Since the beginning of time, words have constantly evolved, and some of their meanings have changed dramatically over time. In this great blog from ideas.ted.com, language historian, Anne Curzan, explores this concept, showing that although it may seem odd, it’s a natural part of linguistic development.

Here are some of the examples she provides of words whose meanings have shifted significantly:

• Nice: Once meant “silly” or “foolish”.
• Silly: Initially described something “worthy” or “blessed”.
• Awful: Originally meant “worthy of awe”.
• Fizzle: Used to mean “quiet flatulence”.
• Myriad: Specifically meant “10,000”.
• Naughty: Described having “nothing”.
• Flirt: Meant “flicking something away”.
• Hussy: Derived from “housewife”.
• Egregious: Meant “distinguished”.
• Senile: Referred to old age generally.
• Meat: Referred to any solid food.

Curzan highlights that while these changes may seem unsettling, they are part of the natural and fascinating evolution of language.