A Japanese dish of steamed, fermented soybeans, with a sticky texture and strong flavour.
The soaked and steamed soybeans are wrapped in rice straw and inoculated with Bacillus natto. Rich in protein, natto was first developed in Buddhist temples as part of a vegetarian diet.
Late 19th century. From Japanese nattō from na(t)- to keep in store, to supply (perhaps here representing nassho temple office from na(t)- + -sho place) + -tō bean; all elements from Middle Chinese.