a member of a Chinese secret society that carried on an unsuccessful uprising, 1898–1900 (Boxer Rebellion), principally against foreigners, culminating in a siege of foreign legations in Peking that was put down by an international expeditionary force.
Origin of Boxer
translation of Chineseyìhé juǎn Righteous Harmony Fist, name of the militant policy of the yìhé tuán Righteous Harmony Group
1900, a name based on mistranslation of Chinese xenophobic society I-He-T'uan, "Righteous Harmony Band," rendered by British as I-He-Ch'uan "Righteous Uniting Fists," and so associated with the pugilistic boxer.
"fighter," late 15c., agent noun from box (v.2). The name of the breed of dog (1934), is from German (the breed originated in Germany), itself taken from English boxer "fighter;" the dog so called for its pugnaciousness. Boxer shorts (1943) so called from their resemblance to the attire worn in the ring.