Daniel assumes chai is a different drink from tea -- the spiced version with milk.

It isn't. Chai and tea are the same word.

They both trace back to a single Chinese character -- 茶 -- that means tea. But Chinese has many varieties of speech, and that same character was pronounced differently in different parts of China. Two of those pronunciations left China by two very different routes -- and that is why the world ended up with two words.

The pronunciation closer to chá traveled overland. Along the Silk Road and related routes it spread westward through Central Asia, Persia, Russia, India, and the Arab world. Persian cha. Russian chai. Turkish çay. Arabic shay. Hindi chai.

The pronunciation closer to te traveled by sea. Dutch traders encountered it at ports in southeastern China and carried it back to Europe as thee. From ...