We literally call ourselves Orthodox Catholic Church.
Western Orthodoxy
They're the only ones who survived
1) fall of rome
2) ottoman empire expansion
It all comes from that
The Church called itself both Catholic and Orthodox in the 1st millenium. "Catholic" was the first common term, understood in the sense of "according to the whole" - every local Church is the whole Church, because Christ is present, sacramentally through the Eucharist and symbolically through the bishop. Later on, "Catholic" caught on in the West (but understood in the sense of "universal", referring to the Church's mission of universal evangelization which is being fulfilled more and more everyday) and "Orthodox" caught in the East ("proper faith/worship", in opposition to heretical sects, especially the Monophysites).
Today the Eastern Orthodox Church officially refers to itself as the "Orthodox Catholic Church" or as the "Eastern Catholic Church". And while the title of "Orthodox" isn't really used in the West anymore, most Eastern Catholic churches call themselves "Orthodox" liturgically. To add to this mess, the Monophysites have decided to call themselves "Oriental Orthodox" since the 1960's.
The title of "Western Orthodox" is unlikely to be used by the Catholics simply because 1) "universal" is already a traditional title and more relevant to the Pope's universal jurisdiction, 2) the title of "Catholic" understood in the Greek sense has been recovered with Vatican II (thanks to the influence of Nicholas Afanasiev), and 3) the Orthodox have called dibs on the "Western Orthodox" title, with their Western Rite.
The Pope took back this title in 1863… and dropped it again in 2006.
Since Chalcedon, they have equal footing with Constantinople.
Such Christian charity.
While Christ prayed The Father's mercy for the men who nailed him to a cross, you pray for fire on men you never knew.
Catholics are hardly Orthodox. They're are fundamentally different on some key theological issues. You can't be orthodox and have different ideas of God, breaking him up in a thousand different energies.. or even disembodying him (i.e. "Heart of Jesus"). Being Orthodox, if anything, is an insistence that you have precision on terms. And there's nothing more important than the word God, first off. They went wrong with the filoque, and continue to do so, with one innovation on top of another.
Besides that, they enshrine Latin and Rome to the point of being clowns. As if the language of Caesar had some kind of inherent holiness to it. Not even the early Roman fathers (the great ones) would be this insistent about enshrining one's own vulgarity.. or forms of government (i.e. things like "Magisterium"). This mess ended up creating a revolt with Protestants, but Orthodox always spoke in common tongues before. It was nothing new. And there's nothing holy about any language.. except the language of angels.
The Oriental Orthodox are not Orthodox either, as they're not better than Catholics. You misunderstand OP's question, I think.
Apologies. But all of those really are different, even immediately to me, in how they approach God. Like I'm in different church.. despite physically resembling each other at times. I think the word "orthodox" was a later word anyhow, made in post schism. So it's a little strange that anyone else adopted it.
They were just called Monophysites by us prior to the 20th century, it's just the diplomatic effeminate ecumenists who call them so.
Catholics often refer to Catholic teaching as orthodoxy. And the Orthodox consider themselves Catholic too. It's just a norm that distinguishes the churches.