Do you ever really think about what words mean and where they come from? Think about a kitchen sink. You're probably imagining three parts. There's a big basin or tub which can be filled with water. (Sometimes there's more than one of these.) Above the basin is a curved or bent pipe which dispenses water, with a little control handle to turn it on & off, and adjust the mixture of heated vs unheated water it dispenses. And then at the bottom of the basin is a hole for water to drain to the sewers, which can also be plugged to keep water in the basin. So: which part of this setup is the "sink". Of course, the whole thing is, that combined device is what we talk about when we say "kitchen sink": "sink" is a synecdoche. But maybe if we think carefully, we might separate the parts one step: the "sink" is the basin & drain, while the water dispensing faucet setup is the "tap". But why call a basin a "sink"? Surely a "sink" is more of synonym for a drainage hole? Unless the term indicates that the basin is below the level of the counter which surrounds it? But that doesn't work either, because you can have a standalone sink without a counter, and it's still called a "sink". And the drainage hole at the bottom of the basin. That's often called a "plug" as a shortening of "plug hole", that is: the hole (which can be plugged) is called a plug (a thing which stops a hole from being a hole). And the water-dispenser? That's called a "tap", presumably in reference to a similar adjustable dispenser put in the side of barrels to make it easier to dose out their contents. But the only thing it's "tap"ping into is a set of water pipes installed for this specific purpose. And when you think closely about it, you might conclude that a "tap" is actually the twisty handle bit which plugs and unplugs a pipe for dispensing water, not the spigot itself. But many kitchen sink "tap"s (that is to say: faucets) don't even have taps on them! They just have a single lever which you twiddle in different directions to control how open the heated & unheated water pipes are, thereby adjusting both temperature and pressure together with one interface. So a kitchen "sink" consists of a basin (the "sink") with a "plug" (a hole) fed by a "tap" (a faucet with no taps). And people wonder why language is so difficult to learn.