Now, that looks a nice simple word.
But is it?
It has at least six different meanings, for a start.
1. A frame-type thing for holding things, or fitting together with other things. This word comes from the Old Norse rekja, to spread out.
2. Destruction. As in rack and ruin. This is partly linked to the meaning above, but also probably to the Middle Dutch wrak, meaning wreckage, and wrack meaning seaweed.
3. A way a horse sometimes moves. From rock (the side-to-side sort of rock), from the Old High German rücken.
4. A group of wind-torn clouds. From the Gothic wraks, meaning, oddly, persecutor.
5. To clear beer or wine by siphoning it off from the dregs. From the Old Provençal arraca, dregs.
6. A neck or rib section of mutton, pork or veal. From the Danish harka, from Swedish harkla to clear the throat.
See? Words borrowed from all over the place - though, typically, we English couldn't pronounce any of them properly and so they all ended up as rack!
Homonyms: words which look and sound the same, but have quite different meanings.
Use some today and confuse everybody!