1.
oolong tea
A traditional Chinese tea that is partially oxidized, widely consumed in Japan as a cold or hot beverage.
ウーロン茶 is one of the most popular non-alcoholic drinks in Japan, available at restaurants, convenience stores, and vending machines.
Writing
Also written as 烏龍茶 in kanji, but the katakana + kanji form (ウーロン茶) is more common.
Cultural note
At 居酒屋 (Japanese pubs), ウーロン茶 is the standard non-alcoholic option. It is also commonly served free at restaurants as an alternative to water.