Wikipedia
Njai
The njai (; Perfected Spelling: nyai) were women who were kept as housekeepers, companions, and concubines in the Dutch East Indies (modern-day Indonesia). In the original Balinese, the word njai meant "sister", but the term later took a more specific meaning. Author Rob Nieuwenhuys described the position of the njai as always subservient, being the white man's housekeeper and companion, before she was his concubine.