Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
dŏmĭnātrix, īcis, f. [dominator], a female ruler, mistress (very rare): caeca ac temeraria dominatrix animi cupiditas, * Cic. Inv. 1, 2, 2: freti (Creta), Sen. Hippol. 85; Vulg. Jerem. 13, 18.