chieftess means synonym of chieftainess: a female chieftain or the wife of a chief. Lexicurio rates it Sui generis — a strength score of 87 out of 100.
Etymology
An irregular form from chief or chieftain + -ess.
noun
- Synonym of chieftainess: a female chieftain or the wife of a chief.“"This heroine was ever after treated by her nation as their deliverer, and made a chieftess in her own right, with the liberty to entail the same honour on her descendants ..." New travels among the Indians of North America, William Fisher, ed., p. 294; attributed to Rev. J. Hubbard. http://books.google.com/books?id=xcIRAAAAYAAJ&pg=PA294&dq=chieftess&hl=en&ei=lUkqTMDcDsL58AaetZ3SCA&sa=X&oi=book_re”