This is kind of the sequel to last week. Because tomorrow is my birthday and I don’t feel like thinking too hard. Also this is my 1,100th post. Kind of impressive.
Cold comes from the Old English cald/ceald, which just means having a low temperature. Or, you know, cold. Ceald is also pronounced with the ch sound, believe it or not, so it used to be chald. Put that with how hot used to have a K and we could have been saying things completely differently. Now, before it was chald, it was the Proto Germanic kaldaz, and that’s where things get muddy. It might be from another Proto Germanic word, kal-/kol-, which in turn comes from the Proto Indo European gel-/gol-. Which, for the record, is in fact where gel and gelatin comes from. But then again kaldaz could be from some random word that got lost to history. We don’t really know for sure.
Cool comes from the Old English col, which is just cool (and evidently is pronounced with a hard K) It comes from the Proto Germanic koluz, which unlike kaldaz is more assuredly from gel-/gol-. Who knows why it’s so definite for one but the other, which seems like it has to be related, is up in the air. Uh…goblins? Yeah, let’s go with goblins.
Chill comes from the Old English cele, coldness. Once again, while there isn’t an H there, it is in fact pronounced with the ch sound. It’s also from the Proto Germanic kal-, yet while cold switched back to the K sound, chill didn’t. Ugh, languages sometimes.
Freeze originally showed up as freese or friese. It comes from the Middle English fresen and Old English freosan. Which means, you know, freeze. Before that it was the Proto Germanic freusan, freeze, and freus. It has a Proto Indo European equivalent in preus, which means that they’re similar, but not necessarily related. Because you don’t want things making too much sense.
TL;DR: Three cold words come from the same word as gel. And then there’s freeze.
Tony Jebson’s page on the Origins of Old English