Language Of Confusion: Vacation, Part I

Gee, I wonder why this is on my mind.
 
Vacate showed up in the mid seventeenth century, from the classical Latin vacatus and its verb form vacare, to be empty or at leisure. Vacation actually showed up much earlier, in the late fourteenth century, from the Old French vacacion and before that, the classical Latin vacationem, another form of vacare. Vacare is from the Proto Indo European wak-, which from the root eue-, to leave, abandon, or give out. And a lot of words with vac- in them are somehow from those three vowels.
 
Vacant showed up in the fourteenth century (vacancy later, in the late sixteenth century). It comes from the Old French vacant, from the classical Latin vacantem, vacant, yet another form of vacare. Then there’s evacuate, which showed up in the early sixteenth century (evacuation showed up earlier, in the fifteenth century, but referred to discharge from the body… ew!). It’s from the classical Latin evacuatus, to make empty, a mix of the prefix ex-, out, and vacuus, empty. To empty out. What a sensible etymology!
 
And of course vacuus gave us vacuum. It showed up in the mid sixteenth century, but only referred to the emptiness of space since vacuums weren’t invented yet (not until 1903!). Vacuum is actually a straight Latin word meaning empty, and is the noun form of vacuus. Vacuous is from the same word, having shown up in the mid seventeenth century, though back then it was literal, not meaning empty of ideas/intelligence until 1848.
 
How straightforward this has all been. I’m sure it will be convoluted again next week.
 
Sources
Online Etymology Dictionary
Google Translate
Omniglot
University of Texas at Austin Linguistic Research Center
University of Texas at San Antonio’s page on Proto Indo European language