Why is tea called tea?
Actually, there are two main ways to refer to tea across the world, namely “tea” or “chai”. Tea originated from China about 4500 years ago. There were records documenting the medicinal use of the tea plant as early as the Shang dynasty (1500 BC).
About the word “tea”: it's a beverage commonly prepared by pouring hot or boiling water over cured leaves of the Camellia sinensis.
At the beginning of its colonial period in the 16th century, Portugal was the first country to bring the habit of tea drinking to Europe. At the time, the Portuguese were involved in trade with Central China and Guangdong. The local word for tea there is “cha”, so the Portuguese adopted this way of calling it all across its other colonies, such as South America etc. Likewise, the word “chai” also entered Russia and the Arabic countries by way of foreign trading.
At the end of 16th century during the Qing dynasty, China and Japan had declared a strict ban on maritime travel. Back when Zheng Chenggong (better known in the West by his Hokkien honorific Koxinga or Coxinga) hadn't taken the island of Taiwan yet, it was full of Spanish and Dutch colonizers. They had their colonial possessions in areas like Malaysia, Philippines etc., too. Because Fujian province's proximity to Taiwan and its low potential for agriculture (potatoes hadn't been imported to China yet, so it was very difficult at times to survive in Fujian), the locals, therefore, were willing to do risky businesses in foreign trading (tea used to be a smuggling product then). As the tea was pronounced “te” in the local Minnan dialect, those Spanish and Dutch colonizers started to use that name. And because in the 16-17th centuries the Netherlands were dominating the trading roots with East and Southeast Asia, the word quickly spread across Spain, France, Germany, Italy, England, and their respective colonies.
So, if you color the countries on the map according to their pronunciation for “tea”, it will be a testament to their capitalist, colonization past.
(Source from Reddit user Bezbojnicul)
You can see that, except for Portugal, it's basically “tea” everywhere, credit to the Netherlands and Spain. And not only it's “chai” in Portugal, it's “chai” in the former Portuguese colonies such as West Africa, some areas in South America etc (pronunciation in the Eastern European countries is affected by Russia's earlier trade routes).
Now in the U.S., some people and businesses refer ”chai” as black tea with milk and sugar, or with honey. So then “tea” specifically refers to a drink brewed from raw tea leaves.
Whenever I tell this story to a foreign friend, it reminds me how connected we all are.