I’ve had these words on the brain lately. Possibly because I keep finding them in my MS.
Shook showed up in 1891, which is relatively recent. It comes from shake, which is much older, having shown up in the fourteenth century. It comes from the Old English sceacan, which could mean shake, or move something, or depart. The earliest language that it was known was as the Proto Germanic skakanan. Although that doesn’t necessarily mean that they were the one who came up with it.
Yes, these words are also connected. Tremor showed up in the late fourteenth century meaning terror, which seems weird, but it comes from the Old French tremor, which could mean terror or quaking (I guess a tremor is something you fear). It comes from the classical Latin tremorem (tremor), which is from the verb tremere, to shiver or tremble. Which brings tremble into the picture. It also showed up in the fourteenth century, and also from the Old French, in this case trembler. It came to us from the Vulgar Latin tremulare, which was from the classical Latin tremulus (trembling), which again is derived from tremere. Tremere can actually be traced to the Proto Indo European trem-, to tremble, so this word has stayed remarkably static over the millennia.
Shiver has two definitions, one that means splinter, and the other that means shake, and as far as I can tell, they aren’t related. The shaking shiver showed up in the fifteenth century as an alteration of chiveren, which meant shiver and showed up in the thirteenth century. Before that it’s a big old question mark. Like shake, it just kind of appeared one day.
Shudder showed up in the early fourteenth century, but not much is known about where it comes from. It might be from the Middle Dutch schuderen, to shudder, or the MiddleLow German schoderen, both of which come from the Proto Germanic skuth-, to shake. But that’s not for sure, no matter how much it seems to make sense.
Quiver showed up in the late fifteenth century and before you ask, no, it’s not related to the thing you hold arrows in. That one is French in origin and this one is… well, probably not. No one’s really sure where it came from. It might be imitative, which means that people thought that shivering sounded like quiver. Or it might be related to quaver, which is a vocal tremor. That does make sense, but as a third option it could be from the Old English cwifer, which I couldn’t find a definition for, unfortunately.
Tony Jebson’s page on the Origins of Old English