Meaning of TRIAD in English
Term used variously for secret societies in Qing-dynasty China (and sometimes earlier), for modern Chinese crime gangs, and for crime gangs of other Asian nationals operating in their own countries or abroad.
A secret society with the name Triad started operating in the early 19th century in southern China, where it took root and spread. In the 1850s Triad rebellions threatened Shanghai and Xiamen (Amoy) and contributed to the revolution of 1911. Chinese secret societies have in common the swearing of an oath to join, strict rules, a family relationship among members, the duty of mutual help, a hierarchy of functions, and hereditary membership within families.
Britannica Concise Encyclopedia. Краткая энциклопедия Британика. 2012