Xinomavro (also often spelled Xynomavro) is a red-wine grape originating in Greece, more particularly in northwestern Greece, in the Imathia region of Macedonia, in what are now the monovarietal appellations of Naoussa and Amynteo; Naoussa is often regarded the best source. Xinomavro is generally considered one of the dozen and a half or so of world-class red-wine grapes (those in boldface in the varietals list to the left of the page).
Xinomavro is not a wine of our times (in any sense). It is a tricky devil in the vineyard: if the vineyardist lets it go, hoping to obtain quantity, quality takes a nosedive, and thin, acidic plonk results; but neither can it be made into the sort of huge Parkerized, internationalized, Shiraz-like red that is so popular today. It can only, made with care and skill, be itself, a red more like Pinot Noir or Nebbiolo in that it trades on delicacy and requires some nontrivial bottle age to get to where it should be.
Nor is it a fruit-forward “jammy” wine: its flavors are (as you will se below) variously described, but almost never in red-fruit terms. Tomato, olive, spice, and earthiness are the recurring descriptors. And it is high-acid and high in tannins (which is why it both bears and usually requires that bottle aging). If you are interested in wines that require some care from both the wine maker and the wine drinker, this will be your sort of wine; if you want a fruit bomb, look elsewhere.
At least one writer observes that there are now two distinct styles of Xinomavro emerging: “traditional”, with high tannins and a need for nontrivial amounts of bottle aging; and “modern”, vinified to be more fruit-forward and drinkable young. That last is relatively new, and it looks like many observers think it inappropriate for this varietal (though there are certainly at least a few successful versions).