Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
impĕrātrix (inp-), īcis, f. [imperator], she who commands, a mistress (very rare): deinde fortes viros ab imperatrice (i. e. Clodia) in insidiis locatos, * Cic. Cael. 28, 67: Italia, Plin. 26, 3, 8, § 16 (dub.; creatrice, Jan.): ut esset animae tam quam imperatrici suae caro subditiva, Ambros. de Inst. Virg. 2, § 11: imperatrix et Augusta Pulcheria, Leo. M. Ep. 101, 3; 98, 3.