Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
* exercĭtātrix, īcis, f. [exercitator], that which exercises the body, gymnastics: duas partes civilitatis corpori assignet (Plato), medicinam et quam interpretantur exercitatricem, Quint. 2, 15, 25.