What English sometimes does when it encounters words in other languages that it already has a word for is to use that word to refer to a specific type of that thing. It’s like distinguishing between what English speakers consider the prototype of the word in English from what we consider non-prototypical.
(Sidenote: prototype theory means that people think of the most prototypical instances of a thing before they think of weirder types. For example: list four kinds of birds to yourself right now. You probably started with local songbirds, which for me is robins, blue birds, cardinals, starlings. If I had you list three more, you might say pigeons or eagles or falcons. It would probably take you a while to get to penguins and emus and ducks, even though those are all birds too. A duck or a penguin, however, is not a prototypical bird.)
“Chai” means tea in Hindi-Urdu, but “chai tea” in English means “tea prepared like masala chai” because it’s useful to have a word to distinguish “the kind of tea we make here” from “the kind of tea they make somewhere else”.
“Naan” may mean bread, but “naan bread” means specifically “bread prepared like this” because it’s useful to have a word to distinguish between “bread made how we make it” and “bread how other people make it”.
We also sometimes say “liege lord” when talking about feudal homage, even though “liege” is just “lord” in French, or “flower blossom” to describe the part of the flower that opens, even though when “flower” was borrowed from French it meant the same thing as blossom.
We also do this with place names: “brea” means tar in Spanish, but when we came across a place where Spanish-speakers were like “there’s tar here”, we took that and said “Okay, here’s the La Brea tar pits”.
Or “Sahara”. Sahara already meant “giant desert,” but we call it the Sahara desert to distinguish it from other giant deserts, like the Gobi desert (Gobi also means desert btw).
English doesn’t seem to be the only language that does this for places: this page has Spanish, Icelandic, Indonesian, and other languages doing it too.
Languages tend to use a lot of repetition to make sure that things are clear. English says “John walks”, and the -s on walks means “one person is doing this” even though we know “John” is one person. Spanish puts tense markers on every instance of a verb in a sentence, even when it’s abundantly clear that they all have the same tense (”ayer [yo] caminé por el parque y jugué tenis” even though “ayer” means yesterday and “yo” means I and the -é means “I in the past”). English apparently also likes to use semantic repetition, so that people know that “chai” is a type of tea and “naan” is a type of bread and “Sahara” is a desert. (I could also totally see someone labeling something, for instance, pan dulce sweetbread, even though “pan dulce” means “sweet bread”.)
Also, specifically with the chai/tea thing, many languages either use the Malay root and end up with a word that sounds like “tea” (like té in Spanish), or they use the Mandarin root and end up with a word that sounds like “chai” (like cha in Portuguese).
