How are you feeling today? Are you fit as a fiddle? Perhaps you're right as rain? Or are you a bit blue around the gills? Could you be under the weather?
What in the world are we talking about? You don't play the fiddle. It's not raining outside. You don't have gills like a fish. Isn't the weather always above us? Are we just talking nonsense?
If you've ever heard someone say they're under the weather, rest assured this expression has nothing to do with hail, sleet, or snow. Instead, people say "under the weather" to express that they're feeling ill or unwell.
"Under the weather" — and the other phrases used above — are idioms. Idioms are phrases whose meaning is different from the meaning of the words themselves.
For example, the words "under the weather" themselves might conjure up an image of someone standing under a raincloud. So how did they come to mean someone isn't feeling well?
Historians believe this idiom comes from the sea. In the days before airplanes, people usually traveled by ship.
During storms, the seas would get rough, causing ships to rock back and forth. The rocking motion often caused passengers to become seasick.
Seasick passengers would head below deck to a lower point where the rocking was less noticeable. Passengers were thus forced under the deck by the weather…and the expression "under the weather" was born!