Language Of Confusion: Armed, Part V

The final part on words descended from the Proto Indo European ar-, to fit together. Now I’m going to have to come up with something new.
 
The first is arthropod—yes, like an insect, spider, or crustacean (one of the reasons I won’t eat them). The word showed up in 1862, though the phylum name Arthropoda showed up in 1849. That’s taken straight from the classical Latin, which literally means those with joined feet. The -poda part means foot and is from the Proto Indo European ped-, while the arthro- is from the Greek, a joint, and that’s from ar-. So because many feet are joined together, we have arthropod.
 
Next somehow is aristocracy, which showed up in the mid sixteenth century from the French aristocracie. That’s from the Late Latin aristocratia, which is from the Greek aristokratia, which just means aristocracy. -Cracy means rule or government, from the Greek Kartos, strength, while aristo- is from aristros, optimal or best. And aristos just happens to be from ar-, though I don’t quite get how best/optimal comes from to fit together.
 
Then there’s alarm, which showed up in the late fourteenth century meaning a call to arms, which then transformed into meaning a warning. It comes from the Old French alarme, which is from the Italian all’arme, short for alle arme, to arms, which is something you’d yell as a warning. The first a in alle means to, then the le is from the Latin ille, the, and arme is from arma, weapons, one of the first words we talked about. At least this one makes sense.
 
You probably wouldn’t think adorn is from there, but it is. It showed up in the late fourteenth century from the Old French aorner, from the classical Latin adornare, to equip or furnish. The ad- means to, and ornare means to decorate and is from ordo, the origin of order.
 
Inert (of all things) showed up in the mid seventeenth century from the French inerte and classical Latin inertem. The in- means not or opposite of, and the rest is from ars, also known as art. Yes, inert is non-art.
 
Finally, the word I personally find to be the weirdest: harmony. Though harmonizing is fitting melodies together. Anyway, it showed up in the late fourteenth century from the classical Latin harmonia. That’s taken right from the Greek version of the word, which is from harmos, a joint or shoulder, which is from ar-. Harmony, once things literally fitting together, and now music doing so.
 
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
Orbis Latinus