Word of the Day: Cog
A cog is part of a gear. Most people know what a gear looks like. You can see on in the picture that accompanies this post or, if you have some small change in your pocket, you can look at a five-yen coin.
On the five yen coin, there is a stalk of wheat, water and around the hole in the middle, there is a gear.
We can easily tell that it’s a gear by the teeth.
So there you have it, cogs, those little pieces that stick out, are the teeth of a gear; they’re the tooth-like parts of gears that fit together with other gears and make each other move.
They are tiny but essential parts of a machine. If one little cog breaks, the machine will fail work properly. It might even stop working altogether.
Why do you need to know this? Well, if I didn’t first explain today’s word, then you wouldn’t be able to understand what the idiom a cog in the machine means.