As far as I understand, the largest ocean on Earth is know worldwide as the Pacific Ocean, a name given by Ferdinand Magellan in 1519. However, it is surprising to me that such a name stuck given that it is an ocean that was known for several millennia before then by literate cultures such as those in Japan, China and Korea.
This reminds me a bit of the old internet hacker/cracker argument. Originally "hacking" was a word for any generalized kind of computer tinkering, and had largely positive connotations. However, mass media felt the most interesting facet of hacking was computer security intrusion, and proceeded to act is if that's all the word meant. A lot of us on the internet tried to popularize "cracking" for that, to get hacking's good name back. However, it didn't matter because the people making mass media weren't listening to us, and didn't really care. We old-school "hackers" lost our word.
This story illustrates an old adage that's as important in History as it is in trolling: Its nearly impossible to win a war of words with someone who buys ink by the barrel.
In the case of the Pacific, all those other societies who knew about that ocean before Magellan did not have industrial printing presses. Any discussion they had about it with others using their native terms was restricted to word-of-mouth and very inefficient hand-writing.
When it first became relevant to Europeans was when Magellan's expedition crossed it as part of its circumnavigation of the globe in 1519-1522. He termed it "Pacífico" because it was a much more peaceful body of water than the hazardous waters around the cape of the South American continent.
This date is important because the printing press had been invented about 80 years earlier, and by this time was in heavy use in Europe. While Europeans didn't have much access to the few East Asian manuscripts floating around (and few could read those that were), and next to no access to actual East Asians to talk about it, they were comparatively flooded with their own printed material about it. All of this material of course used their own terms for the ocean. It looks like an early alternative was Sea of Magellan, but they eventually converged on Magellan's name for it, which in English is "Pacific Ocean".
A few languages with other names for that body continue(d) to use them of course, but for those that found themselves in need, one could see where they'd most likely just use a translation or sound-alike for the term used in the foreign-language work they are referencing or translating. Due to Europe's gargantuan lead in printed material, that's typically going to be the European term.
So the reason Europe's name mostly won out was because at the time Europeans had the only culture that was buying ink by the barrel.