Imagine you are playing a game with your friends where you need to draw a line on a big mountain that splits it into two halves. This line needs to run straight from the top all the way down to the bottom without wiggling around.
Now, if you could magically draw that line, you would have created something called a "meridian" which is just a really fancy way of saying a line that goes from the top of the Earth (which is called the North Pole) all the way down to the bottom (which is called the South Pole).
The 114th meridian is just one of these lines that run all the way around the Earth, but it's special because it runs up and down the western side of the planet. And just like how your game demands that the line has to run straight, so do these meridians.
That's basically it! The 114th meridian is just a line that's on the western side of the Earth that goes up and down and helps us figure out where we are on the planet.