For something only recently introduced to China, this ingredient has gathered quite a few names.
S: 小红莓; T: 小紅莓 (xiǎo hóng méi, literally 'small red berries').
酸莓 (suān méi, literally 'sour berries').
蔓越橘 (màn yuè jú, literally 'creeping fruit').
蔓越莓 (màn yuè méi, literally 'creeping berry').
I'm talking Vaccinium macrocarpon, the all-American cranberry. Or maybe not so all-American as you think.
Introduced around 2013 and the fruit slowly becoming known, the import market was hit by trade tariffs and stalled. Imports from Canada and Chile were unaffected and grew and now cranberries are being grown in China in limited but growing amounts.
China grown cranberries
It will be interesting to see what happens in the future.
Most are sold dried and eaten as such although a lot are used in jams and in baked goods, especially 'cookies'.
They're certainly not being eaten as sauce with turkey.