To starve is to die of hunger.

Is there a word for die of thirst?

You can dehydrate or exsiccate without dying, so is there a word that is more precise?

well, you can starve without dying, too…

AHD:

starve
1. To suffer or die from extreme or prolonged lack of food.
2. Informal To be hungry.
3. To suffer from deprivation.
4. Archaic To suffer or die from cold.
5. v. tr.
To cause to starve.
To force to a specified state by starving.

so starve has more and less severe meanings.  

in medicine, without getting into the nitty-gritty details, we would probably say that someone "died of dehydration."  i cannot think of a one-word answer  :(

david

4. Archaic To suffer or die from cold

In the museum that is Northern England some people still use it in this sense.

Presumably it is related to Dutch "sterven", German "sterben" - to die.

JtW.