Wiktionary
wokou
n. (context historical English) Japanese pirates who raided Japan's neighbours in the Late Middle Ages.
Wikipedia
Wokou
Wokou (; Japanese: Wakō; Korean: 왜구 Waegu), which literally translates to "Japanese pirates" or "dwarf pirates", were pirates who raided the coastlines of China, Japan and Korea. Wokou came from a mixture of ethnicities.
The term wokou is a combination of Wō (倭), referring to either dwarfs or pejoratively to the Japanese, and kòu "bandit".