You think you know what it means. I did too. But what if I told you that it originally meant, “mass of rock, a hill.”
Yep. Cloud is from Old English clud, which was used for rocks and heaps of soil. You know, like clod. No one looks at the sky and says there are clods up there, right? We know that means dirt. But clod and cloud are in fact different spellings of the same word. Why?
Well, round about 1300, people in the south of England began to use cloud metaphorically, upon noting that cumulous clouds often look like mountains, hills, and rock formations up in the sky. Until then, the usual Old English word for clouds was weolcan, but apparently the new metaphor stuck and spread. By the year 1475, cloud had completely usurped weolcan, and in fact was no longer used at all for clods of dirt or rock.