Oeste is the Portuguese word for "west." Now, the Latin word is "occidens," but I feel that the Portuguese word, as well as the equivalent term used in many other modern Italic languages is much more Germanic. I'm wondering if perhaps "oeste" can be traced back to the Germanic groups which dominated the Iberian peninsula, as well as much of Europe, in the period following the fall of Rome, in which the Romance languages began to grow distinct from Latin Vulgate. I read on a Spanish website that "oeste" derives directly from the English "west," but I find this hard to believe, considering how it's also reflected in other Romance languages. It seems more likely to me that each Romance language inherited the word from an earlier West, or East Germanic language.
A few comparisons:
Portuguese (Ibero-Romance): oeste
Spanish (Ibero-Romance): oeste
Catalan (Ibero-Romance): oest
French (Gallo-Romance): ouest
Italian (Italo-Dalmatian): ovest
Romanian (Eastern Romance): vest
(note that the voiced labial-velar approximant cannot be denoted by a single letter in any of these Romance languages)
German (West Germanic): westen
Old High German (West Germanic): westar
Dutch (West Germanic): west
Norwegian (North Germanic): vest
Swedish (North Germanic): vaster
I think it's safe to assume that the Proto-Germanic was something like *westan.
I don't know the Proto-Indo-European, but I think that neither "occidens," nor "westar" are from the PIE root for west, considering that no other branch of the Indo-European family (to the best of my knowledge) commonly uses a native word resembling either.
It should also be noted that both Spanish and Portuguese contain direct derivatives of "occidens" as well as this more Germanic word. (occidente, and ocidental, respectively)