[Abnormal f. chief or chieft(ain + -ESS.] A female chief or chieftain.
1878. W. J. J. Spry, Cruise ‘Challenger,’ xvi. (ed. 7), 275. A small party of ladies … amongst whom were … Moa, Queen of Raiatea … the Chieftess of Morea.
1883. E. T. Doane, in Missionary Herald (Boston), Jan. (1884), 37. The … Christian woman and chieftess.
